DataSupport (litepal 1.4.1 API)

java.lang.Object
- org.litepal.crud.DataSupport

```
public class DataSupport
extends java.lang.Object
```
DataSupport connects classes to SQLite database tables to establish an almost zero-configuration persistence layer for applications. In the context of an application, these classes are commonly referred to as models. Models can also be connected to other models.
DataSupport relies heavily on naming in that it uses class and association names to establish mappings between respective database tables and foreign key columns.
Automated mapping between classes and tables, attributes and columns.
```
 public class Person extends DataSupport {
        private int id;
        private String name;
        private int age;
 }
 
 The Person class is automatically mapped to the table named "person",
 which might look like this:
 
 CREATE TABLE person (
        id integer primary key autoincrement,
        age integer, 
        name text
 );
 
```
从以下版本开始:

1.1

构造器概要

构造器
限定符构造器和说明

protected DataSupport()
Disable developers to create instance of DataSupport directly.

构造器
限定符	构造器和说明
`protected`	`DataSupport()` Disable developers to create instance of DataSupport directly.

方法概要

所有方法静态方法实例方法具体方法
限定符和类型	方法和说明
`void`	`assignBaseObjId(int baseObjId)` Assigns value to baseObjId.
`static double`	`average(java.lang.Class<?> modelClass, java.lang.String column)` Calculates the average value on a given column.
`static double`	`average(java.lang.String tableName, java.lang.String column)` Calculates the average value on a given column.
`void`	`clearSavedState()` It model is saved, clear the saved state and model becomes unsaved.
`static int`	`count(java.lang.Class<?> modelClass)` Count the records.
`static int`	`count(java.lang.String tableName)` Count the records.
`int`	`delete()` Deletes the record in the database.
`static int`	`delete(java.lang.Class<?> modelClass, long id)` Deletes the record in the database by id.
`static int`	`deleteAll(java.lang.Class<?> modelClass, java.lang.String... conditions)` Deletes all records with details given if they match a set of conditions supplied.
`static int`	`deleteAll(java.lang.String tableName, java.lang.String... conditions)` Deletes all records with details given if they match a set of conditions supplied.
`static <T> T`	`find(java.lang.Class<T> modelClass, long id)` Finds the record by a specific id.
`static <T> T`	`find(java.lang.Class<T> modelClass, long id, boolean isEager)` It is mostly same as `find(Class, long)` but an isEager parameter.
`static <T> java.util.List<T>`	`findAll(java.lang.Class<T> modelClass, boolean isEager, long... ids)` It is mostly same as `findAll(Class, long...)` but an isEager parameter.
`static <T> java.util.List<T>`	`findAll(java.lang.Class<T> modelClass, long... ids)` Finds multiple records by an id array.
`static android.database.Cursor`	`findBySQL(java.lang.String... sql)` Runs the provided SQL and returns a Cursor over the result set.
`static <T> T`	`findFirst(java.lang.Class<T> modelClass)` Finds the first record of a single table.
`static <T> T`	`findFirst(java.lang.Class<T> modelClass, boolean isEager)` It is mostly same as `findFirst(Class)` but an isEager parameter.
`static <T> T`	`findLast(java.lang.Class<T> modelClass)` Finds the last record of a single table.
`static <T> T`	`findLast(java.lang.Class<T> modelClass, boolean isEager)` It is mostly same as `findLast(Class)` but an isEager parameter.
`protected long`	`getBaseObjId()` Get the baseObjId of this model if it's useful for developers.
`protected java.lang.String`	`getClassName()` Get the full class name of self.
`protected java.lang.String`	`getTableName()` Get the corresponding table name of current model.
`static <T> boolean`	`isExist(java.lang.Class<T> modelClass, java.lang.String... conditions)` Check if the specified conditions data already exists in the table.
`boolean`	`isSaved()` Current model is saved or not.
`static ClusterQuery`	`limit(int value)` Limits the number of rows returned by the query.
`static <T extends DataSupport> void`	`markAsDeleted(java.util.Collection<T> collection)` Provide a way to mark all models in collection as deleted.
`static <T> T`	`max(java.lang.Class<?> modelClass, java.lang.String columnName, java.lang.Class<T> columnType)` Calculates the maximum value on a given column.
`static <T> T`	`max(java.lang.String tableName, java.lang.String columnName, java.lang.Class<T> columnType)` Calculates the maximum value on a given column.
`static <T> T`	`min(java.lang.Class<?> modelClass, java.lang.String columnName, java.lang.Class<T> columnType)` Calculates the minimum value on a given column.
`static <T> T`	`min(java.lang.String tableName, java.lang.String columnName, java.lang.Class<T> columnType)` Calculates the minimum value on a given column.
`static ClusterQuery`	`offset(int value)` Declaring the offset of rows returned by the query.
`static ClusterQuery`	`order(java.lang.String column)` Declaring how to order the rows queried from table.
`boolean`	`save()` Saves the model.
`static <T extends DataSupport> void`	`saveAll(java.util.Collection<T> collection)` Saves the collection into database.
`boolean`	`saveFast()` Saves the model ignore associations, so that the saving process will be faster.
`boolean`	`saveIfNotExist(java.lang.String... conditions)` Saves the model only when the conditions data not exist.
`void`	`saveThrows()` Saves the model.
`static ClusterQuery`	`select(java.lang.String... columns)` Declaring to query which columns in table.
`void`	`setToDefault(java.lang.String fieldName)` When updating database with `update(long)`, you must use this method to update a field into default value.
`static <T> T`	`sum(java.lang.Class<?> modelClass, java.lang.String columnName, java.lang.Class<T> columnType)` Calculates the sum of values on a given column.
`static <T> T`	`sum(java.lang.String tableName, java.lang.String columnName, java.lang.Class<T> columnType)` Calculates the sum of values on a given column.
`static int`	`update(java.lang.Class<?> modelClass, android.content.ContentValues values, long id)` Updates the corresponding record by id with ContentValues.
`int`	`update(long id)` Updates the corresponding record by id.
`static int`	`updateAll(java.lang.Class<?> modelClass, android.content.ContentValues values, java.lang.String... conditions)` Updates all records with details given if they match a set of conditions supplied.
`int`	`updateAll(java.lang.String... conditions)` Updates all records with details given if they match a set of conditions supplied.
`static int`	`updateAll(java.lang.String tableName, android.content.ContentValues values, java.lang.String... conditions)` Updates all records with details given if they match a set of conditions supplied.
`static ClusterQuery`	`where(java.lang.String... conditions)` Declaring to query which rows in table.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 构造器详细资料
  - DataSupport
```
protected DataSupport()
```
    Disable developers to create instance of DataSupport directly. They should inherit this class with subclasses and operate on them.
- 方法详细资料
  - select
```
public static ClusterQuery select(java.lang.String... columns)
```
    Declaring to query which columns in table.
```
 DataSupport.select("name", "age").find(Person.class);
 
```
    This will find all rows with name and age columns in Person table.
    参数:
    
    columns - A String array of which columns to return. Passing null will return all columns.
    
    返回:
    
    A ClusterQuery instance.
  - where
```
public static ClusterQuery where(java.lang.String... conditions)
```
    Declaring to query which rows in table.
```
 DataSupport.where("name = ? or age > ?", "Tom", "14").find(Person.class);
 
```
    This will find rows which name is Tom or age greater than 14 in Person table.
    参数:
    
    conditions - A filter declaring which rows to return, formatted as an SQL WHERE clause. Passing null will return all rows.
    
    返回:
    
    A ClusterQuery instance.
  - order
```
public static ClusterQuery order(java.lang.String column)
```
    Declaring how to order the rows queried from table.
```
 DataSupport.order("name desc").find(Person.class);
 
```
    This will find all rows in Person table sorted by name with inverted order.
    参数:
    
    column - How to order the rows, formatted as an SQL ORDER BY clause. Passing null will use the default sort order, which may be unordered.
    
    返回:
    
    A ClusterQuery instance.
  - limit
```
public static ClusterQuery limit(int value)
```
    Limits the number of rows returned by the query.
```
 DataSupport.limit(2).find(Person.class);
 
```
    This will find the top 2 rows in Person table.
    参数:
    
    value - Limits the number of rows returned by the query, formatted as LIMIT clause.
    
    返回:
    
    A ClusterQuery instance.
  - offset
```
public static ClusterQuery offset(int value)
```
    Declaring the offset of rows returned by the query. This method must be used with limit(int), or nothing will return.
```
 DataSupport.limit(1).offset(2).find(Person.class);
 
```
    This will find the third row in Person table.
    参数:
    
    value - The offset amount of rows returned by the query.
    
    返回:
    
    A ClusterQuery instance.
  - count
```
public static int count(java.lang.Class<?> modelClass)
```
    Count the records.
```
 DataSupport.count(Person.class);
 
```
    This will count all rows in person table.
    You can also specify a where clause when counting.
```
 DataSupport.where("age > ?", "15").count(Person.class);
 
```
    参数:
    
    modelClass - Which table to query from by class.
    
    返回:
    
    Count of the specified table.
  - count
```
public static int count(java.lang.String tableName)
```
    Count the records.
```
 DataSupport.count("person");
 
```
    This will count all rows in person table.
    You can also specify a where clause when counting.
```
 DataSupport.where("age > ?", "15").count("person");
 
```
    参数:
    
    tableName - Which table to query from.
    
    返回:
    
    Count of the specified table.
  - average
```
public static double average(java.lang.Class<?> modelClass,
                             java.lang.String column)
```
    Calculates the average value on a given column.
```
 DataSupport.average(Person.class, "age");
 
```
    You can also specify a where clause when calculating.
```
 DataSupport.where("age > ?", "15").average(Person.class, "age");
 
```
    参数:
    
    modelClass - Which table to query from by class.
    
    column - The based on column to calculate.
    
    返回:
    
    The average value on a given column.
  - average
```
public static double average(java.lang.String tableName,
                             java.lang.String column)
```
    Calculates the average value on a given column.
```
 DataSupport.average("person", "age");
 
```
    You can also specify a where clause when calculating.
```
 DataSupport.where("age > ?", "15").average("person", "age");
 
```
    参数:
    
    tableName - Which table to query from.
    
    column - The based on column to calculate.
    
    返回:
    
    The average value on a given column.
  - max
```
public static <T> T max(java.lang.Class<?> modelClass,
                        java.lang.String columnName,
                        java.lang.Class<T> columnType)
```
    Calculates the maximum value on a given column. The value is returned with the same data type of the column.
```
 DataSupport.max(Person.class, "age", int.class);
 
```
    You can also specify a where clause when calculating.
```
 DataSupport.where("age > ?", "15").max(Person.class, "age", Integer.TYPE);
 
```
    参数:
    
    modelClass - Which table to query from by class.
    
    columnName - The based on column to calculate.
    
    columnType - The type of the based on column.
    
    返回:
    
    The maximum value on a given column.
  - max
```
public static <T> T max(java.lang.String tableName,
                        java.lang.String columnName,
                        java.lang.Class<T> columnType)
```
    Calculates the maximum value on a given column. The value is returned with the same data type of the column.
```
 DataSupport.max("person", "age", int.class);
 
```
    You can also specify a where clause when calculating.
```
 DataSupport.where("age > ?", "15").max("person", "age", Integer.TYPE);
 
```
    参数:
    
    tableName - Which table to query from.
    
    columnName - The based on column to calculate.
    
    columnType - The type of the based on column.
    
    返回:
    
    The maximum value on a given column.
  - min
```
public static <T> T min(java.lang.Class<?> modelClass,
                        java.lang.String columnName,
                        java.lang.Class<T> columnType)
```
    Calculates the minimum value on a given column. The value is returned with the same data type of the column.
```
 DataSupport.min(Person.class, "age", int.class);
 
```
    You can also specify a where clause when calculating.
```
 DataSupport.where("age > ?", "15").min(Person.class, "age", Integer.TYPE);
 
```
    参数:
    
    modelClass - Which table to query from by class.
    
    columnName - The based on column to calculate.
    
    columnType - The type of the based on column.
    
    返回:
    
    The minimum value on a given column.
  - min
```
public static <T> T min(java.lang.String tableName,
                        java.lang.String columnName,
                        java.lang.Class<T> columnType)
```
    Calculates the minimum value on a given column. The value is returned with the same data type of the column.
```
 DataSupport.min("person", "age", int.class);
 
```
    You can also specify a where clause when calculating.
```
 DataSupport.where("age > ?", "15").min("person", "age", Integer.TYPE);
 
```
    参数:
    
    tableName - Which table to query from.
    
    columnName - The based on column to calculate.
    
    columnType - The type of the based on column.
    
    返回:
    
    The minimum value on a given column.
  - sum
```
public static <T> T sum(java.lang.Class<?> modelClass,
                        java.lang.String columnName,
                        java.lang.Class<T> columnType)
```
    Calculates the sum of values on a given column. The value is returned with the same data type of the column.
```
 DataSupport.sum(Person.class, "age", int.class);
 
```
    You can also specify a where clause when calculating.
```
 DataSupport.where("age > ?", "15").sum(Person.class, "age", Integer.TYPE);
 
```
    参数:
    
    modelClass - Which table to query from by class.
    
    columnName - The based on column to calculate.
    
    columnType - The type of the based on column.
    
    返回:
    
    The sum value on a given column.
  - sum
```
public static <T> T sum(java.lang.String tableName,
                        java.lang.String columnName,
                        java.lang.Class<T> columnType)
```
    Calculates the sum of values on a given column. The value is returned with the same data type of the column.
```
 DataSupport.sum("person", "age", int.class);
 
```
    You can also specify a where clause when calculating.
```
 DataSupport.where("age > ?", "15").sum("person", "age", Integer.TYPE);
 
```
    参数:
    
    tableName - Which table to query from.
    
    columnName - The based on column to calculate.
    
    columnType - The type of the based on column.
    
    返回:
    
    The sum value on a given column.
  - find
```
public static <T> T find(java.lang.Class<T> modelClass,
                         long id)
```
    Finds the record by a specific id.
```
 Person p = DataSupport.find(Person.class, 1);
 
```
    The modelClass determines which table to query and the object type to return. If no record can be found, then return null.
    Note that the associated models won't be loaded by default considering the efficiency, but you can do that by using find(Class, long, boolean).
    参数:
    
    modelClass - Which table to query and the object type to return.
    
    id - Which record to query.
    
    返回:
    
    An object with found data from database, or null.
  - find
```
public static <T> T find(java.lang.Class<T> modelClass,
                         long id,
                         boolean isEager)
```
    It is mostly same as find(Class, long) but an isEager parameter. If set true the associated models will be loaded as well.
    
    参数:
    
    modelClass - Which table to query and the object type to return.
    
    id - Which record to query.
    
    isEager - True to load the associated models, false not.
    
    返回:
    
    An object with found data from database, or null.
  - findFirst
```
public static <T> T findFirst(java.lang.Class<T> modelClass)
```
    Finds the first record of a single table.
```
 Person p = DataSupport.findFirst(Person.class);
 
```
    Note that the associated models won't be loaded by default considering the efficiency, but you can do that by using findFirst(Class, boolean).
    参数:
    
    modelClass - Which table to query and the object type to return.
    
    返回:
    
    An object with data of first row, or null.
  - findFirst
```
public static <T> T findFirst(java.lang.Class<T> modelClass,
                              boolean isEager)
```
    It is mostly same as findFirst(Class) but an isEager parameter. If set true the associated models will be loaded as well.
    
    参数:
    
    modelClass - Which table to query and the object type to return.
    
    isEager - True to load the associated models, false not.
    
    返回:
    
    An object with data of first row, or null.
  - findLast
```
public static <T> T findLast(java.lang.Class<T> modelClass)
```
    Finds the last record of a single table.
```
 Person p = DataSupport.findLast(Person.class);
 
```
    Note that the associated models won't be loaded by default considering the efficiency, but you can do that by using findLast(Class, boolean).
    参数:
    
    modelClass - Which table to query and the object type to return.
    
    返回:
    
    An object with data of last row, or null.
  - findLast
```
public static <T> T findLast(java.lang.Class<T> modelClass,
                             boolean isEager)
```
    It is mostly same as findLast(Class) but an isEager parameter. If set true the associated models will be loaded as well.
    
    参数:
    
    modelClass - Which table to query and the object type to return.
    
    isEager - True to load the associated models, false not.
    
    返回:
    
    An object with data of last row, or null.
  - findAll
```
public static <T> java.util.List<T> findAll(java.lang.Class<T> modelClass,
                                            long... ids)
```
    Finds multiple records by an id array.
```
 List<Person> people = DataSupport.findAll(Person.class, 1, 2, 3);
 
 long[] bookIds = { 10, 18 };
 List<Book> books = DataSupport.findAll(Book.class, bookIds);
 
```
    Of course you can find all records by passing nothing to the ids parameter.
```
 List<Book> allBooks = DataSupport.findAll(Book.class);
 
```
    Note that the associated models won't be loaded by default considering the efficiency, but you can do that by using findAll(Class, boolean, long...). The modelClass determines which table to query and the object type to return.
    参数:
    
    modelClass - Which table to query and the object type to return as a list.
    
    ids - Which records to query. Or do not pass it to find all records.
    
    返回:
    
    An object list with found data from database, or an empty list.
  - findAll
```
public static <T> java.util.List<T> findAll(java.lang.Class<T> modelClass,
                                            boolean isEager,
                                            long... ids)
```
    It is mostly same as findAll(Class, long...) but an isEager parameter. If set true the associated models will be loaded as well.
    
    参数:
    
    modelClass - Which table to query and the object type to return as a list.
    
    isEager - True to load the associated models, false not.
    
    ids - Which records to query. Or do not pass it to find all records.
    
    返回:
    
    An object list with found data from database, or an empty list.
  - findBySQL
```
public static android.database.Cursor findBySQL(java.lang.String... sql)
```
    Runs the provided SQL and returns a Cursor over the result set. You may include ?s in where clause in the query, which will be replaced by the second to the last parameters, such as:
```
 Cursor cursor = DataSupport.findBySQL("select * from person where name=? and age=?", "Tom", "14");
 
```
    参数:
    
    sql - First parameter is the SQL clause to apply. Second to the last parameters will replace the place holders.
    
    返回:
    
    A Cursor object, which is positioned before the first entry. Note that Cursors are not synchronized, see the documentation for more details.
  - delete
```
public static int delete(java.lang.Class<?> modelClass,
                         long id)
```
    Deletes the record in the database by id.
    The data in other tables which is referenced with the record will be removed too.
```
 DataSupport.delete(Person.class, 1);
 
```
    This means that the record 1 in person table will be removed.
    参数:
    
    modelClass - Which table to delete from by class.
    
    id - Which record to delete.
    
    返回:
    
    The number of rows affected. Including cascade delete rows.
  - deleteAll
```
public static int deleteAll(java.lang.Class<?> modelClass,
                            java.lang.String... conditions)
```
    Deletes all records with details given if they match a set of conditions supplied. This method constructs a single SQL DELETE statement and sends it to the database.
```
 DataSupport.deleteAll(Person.class, "name = ? and age = ?", "Tom", "14");
 
```
    This means that all the records which name is Tom and age is 14 will be removed.
    参数:
    
    modelClass - Which table to delete from by class.
    
    conditions - A string array representing the WHERE part of an SQL statement. First parameter is the WHERE clause to apply when deleting. The way of specifying place holders is to insert one or more question marks in the SQL. The first question mark is replaced by the second element of the array, the next question mark by the third, and so on. Passing empty string will update all rows.
    
    返回:
    
    The number of rows affected.
  - deleteAll
```
public static int deleteAll(java.lang.String tableName,
                            java.lang.String... conditions)
```
    Deletes all records with details given if they match a set of conditions supplied. This method constructs a single SQL DELETE statement and sends it to the database.
```
 DataSupport.deleteAll("person", "name = ? and age = ?", "Tom", "14");
 
```
    This means that all the records which name is Tom and age is 14 will be removed.
    Note that this method won't delete the referenced data in other tables. You should remove those values by your own.
    参数:
    
    tableName - Which table to delete from.
    
    conditions - A string array representing the WHERE part of an SQL statement. First parameter is the WHERE clause to apply when deleting. The way of specifying place holders is to insert one or more question marks in the SQL. The first question mark is replaced by the second element of the array, the next question mark by the third, and so on. Passing empty string will update all rows.
    
    返回:
    
    The number of rows affected.
  - update
```
public static int update(java.lang.Class<?> modelClass,
                         android.content.ContentValues values,
                         long id)
```
    Updates the corresponding record by id with ContentValues. Returns the number of affected rows.
```
 ContentValues cv = new ContentValues();
 cv.put("name", "Jim");
 DataSupport.update(Person.class, cv, 1);
 
```
    This means that the name of record 1 will be updated into Jim.
    参数:
    
    modelClass - Which table to update by class.
    
    values - A map from column names to new column values. null is a valid value that will be translated to NULL.
    
    id - Which record to update.
    
    返回:
    
    The number of rows affected.
  - updateAll
```
public static int updateAll(java.lang.Class<?> modelClass,
                            android.content.ContentValues values,
                            java.lang.String... conditions)
```
    Updates all records with details given if they match a set of conditions supplied. This method constructs a single SQL UPDATE statement and sends it to the database.
```
 ContentValues cv = new ContentValues();
 cv.put("name", "Jim");
 DataSupport.update(Person.class, cv, "name = ?", "Tom");
 
```
    This means that all the records which name is Tom will be updated into Jim.
    参数:
    
    modelClass - Which table to update by class.
    
    values - A map from column names to new column values. null is a valid value that will be translated to NULL.
    
    conditions - A string array representing the WHERE part of an SQL statement. First parameter is the WHERE clause to apply when updating. The way of specifying place holders is to insert one or more question marks in the SQL. The first question mark is replaced by the second element of the array, the next question mark by the third, and so on. Passing empty string will update all rows.
    
    返回:
    
    The number of rows affected.
  - updateAll
```
public static int updateAll(java.lang.String tableName,
                            android.content.ContentValues values,
                            java.lang.String... conditions)
```
    Updates all records with details given if they match a set of conditions supplied. This method constructs a single SQL UPDATE statement and sends it to the database.
```
 ContentValues cv = new ContentValues();
 cv.put("name", "Jim");
 DataSupport.update("person", cv, "name = ?", "Tom");
 
```
    This means that all the records which name is Tom will be updated into Jim.
    参数:
    
    tableName - Which table to update.
    
    values - A map from column names to new column values. null is a valid value that will be translated to NULL.
    
    conditions - A string array representing the WHERE part of an SQL statement. First parameter is the WHERE clause to apply when updating. The way of specifying place holders is to insert one or more question marks in the SQL. The first question mark is replaced by the second element of the array, the next question mark by the third, and so on. Passing empty string will update all rows.
    
    返回:
    
    The number of rows affected.
  - saveAll
```
public static <T extends DataSupport> void saveAll(java.util.Collection<T> collection)
```
    Saves the collection into database.
```
 DataSupport.saveAll(people);
 
```
    If the model in collection is a new record gets created in the database, otherwise the existing record gets updated.
    If saving process failed by any accident, the whole action will be cancelled and your database will be rolled back.
    This method acts the same result as the below way, but much more efficient.
```
 for (Person person : people) {
        person.save();
 }
 
```
    So when your collection holds huge of models, saveAll(java.util.Collection) is the better choice.
    参数:
    
    collection - Holds all models to save.
  - markAsDeleted
```
public static <T extends DataSupport> void markAsDeleted(java.util.Collection<T> collection)
```
    Provide a way to mark all models in collection as deleted. This means these models' save state is no longer exist anymore. If save them again, they will be treated as inserting new data instead of updating the exist one.
    
    参数:
    
    collection - Collection of models which want to mark as deleted and clear their save state.
  - isExist
```
public static <T> boolean isExist(java.lang.Class<T> modelClass,
                                  java.lang.String... conditions)
```
    Check if the specified conditions data already exists in the table.
    
    参数:
    
    modelClass - Which table to check by class.
    
    conditions - A filter declaring which data to check. Exactly same use as where(String...), except null conditions will result in false.
    
    返回:
    
    Return true if the specified conditions data already exists in the table. False otherwise. Null conditions will result in false.
  - delete
```
public int delete()
```
    Deletes the record in the database. The record must be saved already.
    The data in other tables which is referenced with the record will be removed too.
```
 Person person;
 ....
 if (person.isSaved()) {
                person.delete();
 }
 
```
    返回:
    
    The number of rows affected. Including cascade delete rows.
  - update
```
public int update(long id)
```
    Updates the corresponding record by id. Use setXxx to decide which columns to update.
```
 Person person = new Person();
 person.setName("Jim");
 person.update(1);
 
```
    This means that the name of record 1 will be updated into Jim.
    Note: 1. If you set a default value to a field, the corresponding column won't be updated. Use setToDefault(String) to update columns into default value. 2. This method couldn't update foreign key in database. So do not use setXxx to set associations between models.
    参数:
    
    id - Which record to update.
    
    返回:
    
    The number of rows affected.
  - updateAll
```
public int updateAll(java.lang.String... conditions)
```
    Updates all records with details given if they match a set of conditions supplied. This method constructs a single SQL UPDATE statement and sends it to the database.
```
 Person person = new Person();
 person.setName("Jim");
 person.updateAll("name = ?", "Tom");
 
```
    This means that all the records which name is Tom will be updated into Jim.
    Note: 1. If you set a default value to a field, the corresponding column won't be updated. Use setToDefault(String) to update columns into default value. 2. This method couldn't update foreign key in database. So do not use setXxx to set associations between models.
    参数:
    
    conditions - A string array representing the WHERE part of an SQL statement. First parameter is the WHERE clause to apply when updating. The way of specifying place holders is to insert one or more question marks in the SQL. The first question mark is replaced by the second element of the array, the next question mark by the third, and so on. Passing empty string will update all rows.
    
    返回:
    
    The number of rows affected.
  - save
```
public boolean save()
```
    Saves the model.
```
 Person person = new Person();
 person.setName("Tom");
 person.setAge(22);
 person.save();
 
```
    If the model is a new record gets created in the database, otherwise the existing record gets updated.
    If saving process failed by any accident, the whole action will be cancelled and your database will be rolled back.
    If the model has a field named id or _id and field type is int or long, the id value generated by database will assign to it after the model is saved.
    Note that if the associated models of this model is already saved. The associations between them will be built automatically in database after it saved.
    返回:
    
    If the model is saved successfully, return true. Any exception happens, return false.
  - saveThrows
```
public void saveThrows()
```
    Saves the model.
```
 Person person = new Person();
 person.setName("Tom");
 person.setAge(22);
 person.saveThrows();
 
```
    If the model is a new record gets created in the database, otherwise the existing record gets updated.
    If saving process failed by any accident, the whole action will be cancelled and your database will be rolled back and throws DataSupportException
    If the model has a field named id or _id and field type is int or long, the id value generated by database will assign to it after the model is saved.
    Note that if the associated models of this model is already saved. The associations between them will be built automatically in database after it saved.
    抛出:
    
    DataSupportException
  - saveIfNotExist
```
public boolean saveIfNotExist(java.lang.String... conditions)
```
    Saves the model only when the conditions data not exist.
```
 Person person = new Person();
 person.setName("Tom");
 person.setAge(22);
 person.saveIfNotExists("name = ?", "Tom");
 
```
    If person table doesn't have a name with Tom, a new record gets created in the database, otherwise the saving operation will be ignored.
    If saving process failed by any accident, the whole action will be cancelled and your database will be rolled back.
    If the model has a field named id or _id and field type is int or long, the id value generated by database will assign to it after the model is saved.
    Note that if the associated models of this model is already saved. The associations between them will be built automatically in database after it saved.
    返回:
    
    If the model is saved successfully, return true. If the conditions data already exist or any exception happens, return false.
  - saveFast
```
public boolean saveFast()
```
    Saves the model ignore associations, so that the saving process will be faster.
```
 Person person = new Person();
 person.setName("Tom");
 person.setAge(22);
 person.save();
 
```
    If the model is a new record gets created in the database, otherwise the existing record gets updated.
    If saving process failed by any accident, the whole action will be cancelled and your database will be rolled back.
    If the model has a field named id or _id and field type is int or long, the id value generated by database will assign to it after the model is saved.
    If your model doesn't has any association, you can use this method to save faster.
    返回:
    
    If the model is saved successfully, return true. Any exception happens, return false.
  - isSaved
```
public boolean isSaved()
```
    Current model is saved or not.
    
    返回:
    
    If saved return true, or return false.
  - clearSavedState
```
public void clearSavedState()
```
    It model is saved, clear the saved state and model becomes unsaved. Otherwise nothing will happen.
  - setToDefault
```
public void setToDefault(java.lang.String fieldName)
```
    When updating database with update(long), you must use this method to update a field into default value. Use setXxx with default value of the model won't update anything.
    
    参数:
    
    fieldName - The name of field to update into default value.
  - assignBaseObjId
```
public void assignBaseObjId(int baseObjId)
```
    Assigns value to baseObjId. This will override the original value. Never call this method unless you know exactly what you are doing.
    
    参数:
    
    baseObjId -
  - getBaseObjId
```
protected long getBaseObjId()
```
    Get the baseObjId of this model if it's useful for developers. It's for system use usually. Do not try to assign or modify it.
    
    返回:
    
    The base object id.
  - getClassName
```
protected java.lang.String getClassName()
```
    Get the full class name of self.
    
    返回:
    
    The full class name of self.
  - getTableName
```
protected java.lang.String getTableName()
```
    Get the corresponding table name of current model.
    
    返回:
    
    The corresponding table name of current model.

类 DataSupport

构造器概要

方法概要

从类继承的方法 java.lang.Object

构造器详细资料

DataSupport

方法详细资料

select

where

order

limit

offset

count

count

average

average

max

max

min

min

sum

sum

find

find

findFirst

findFirst

findLast

findLast

findAll

findAll

findBySQL

delete

deleteAll

deleteAll

update

updateAll

updateAll

saveAll

markAsDeleted

isExist

delete

update

updateAll

save

saveThrows

saveIfNotExist

saveFast

isSaved

clearSavedState

setToDefault

assignBaseObjId

getBaseObjId

getClassName

getTableName