Package org.apache.cayenne.dba

## Interface DbAdapter

- All Known Implementing Classes:
    `AutoAdapter`, `DB2Adapter`, `DerbyAdapter`, `FirebirdAdapter`, `FrontBaseAdapter`, `H2Adapter`, `HSQLDBAdapter`, `HSQLDBNoSchemaAdapter`, `IngresAdapter`, `JdbcAdapter`, `MySQLAdapter`, `OpenBaseAdapter`, `Oracle8Adapter`, `OracleAdapter`, `PostgresAdapter`, `SQLiteAdapter`, `SQLServerAdapter`, `SybaseAdapter`

      public interface DbAdapter

  A Cayenne extension point that abstracts the differences between specifics of JDBC interfaces to various databases. Cayenne already ships with a number of built-in adapters for most common databases and users can provide their own custom adapters.

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `void` | `bindParameter​(PreparedStatement statement, ParameterBinding parameterBinding)` | Binds an object value to PreparedStatement's parameter.
    `DbAttribute` | `buildAttribute​(String name, String typeName, int type, int size, int scale, boolean allowNulls)` | Creates and returns a DbAttribute based on supplied parameters (usually obtained from database meta data).
    `String` | `createFkConstraint​(DbRelationship rel)` | Returns a SQL string that can be used to create a foreign key constraint for the relationship, or null if foreign keys are not supported.
    `String` | `createTable​(DbEntity entity)` | Returns a SQL string that can be used to create database table corresponding to `entity` parameter.
    `void` | `createTableAppendColumn​(StringBuffer sqlBuffer, DbAttribute column)` | Append the column type part of a "create table" to the given `StringBuffer`
    `String` | `createUniqueConstraint​(DbEntity source, Collection<DbAttribute> columns)` | Returns a DDL string to create a unique constraint over a set of columns, or null if the unique constraints are not supported.
    `Collection<String>` | `dropTableStatements​(DbEntity table)` | Returns a collection of SQL statements needed to drop a database table.
    `String[]` | `externalTypesForJdbcType​(int type)` | Returns an array of RDBMS types that can be used with JDBC `type`.
    `SQLAction` | `getAction​(Query query, DataNode node)` | Returns an instance of SQLAction that should handle the query.
    `String` | `getBatchTerminator()` | Returns a String used to terminate a batch in command-line tools.
    `EJBQLTranslatorFactory` | `getEjbqlTranslatorFactory()` | Returns a translator factory for EJBQL to SQL translation.
    `ExtendedTypeMap` | `getExtendedTypes()` | Returns a map of ExtendedTypes that is used to translate values between Java and JDBC layer.
    `PkGenerator` | `getPkGenerator()` | Returns primary key generator associated with this DbAdapter.
    `QualifierTranslator` | `getQualifierTranslator​(QueryAssembler queryAssembler)` |
    `QuotingStrategy` | `getQuotingStrategy()` | Returns SQL identifier quoting strategy object
    `SelectTranslator` | `getSelectTranslator​(SelectQuery<?> query, EntityResolver entityResolver)` | Returns a SelectTranslator that works with the adapter target database.
    `List<String>` | `getSystemCatalogs()` |
    `List<String>` | `getSystemSchemas()` |
    `void` | `setPkGenerator​(PkGenerator pkGenerator)` | Set custom PK generator associated with this DbAdapter.
    `boolean` | `supportsBatchUpdates()` | Returns `true` if the target database supports batch updates.
    `boolean` | `supportsCatalogsOnReverseEngineering()` | Returns true if a target database supports catalogs on reverse engineering.
    `boolean` | `supportsGeneratedKeys()` | Returns true if a target database supports key autogeneration.
    `boolean` | `supportsUniqueConstraints()` | Returns true if a target database supports UNIQUE constraints.
    `String` | `tableTypeForTable()` | Returns the name of the table type (as returned by `DatabaseMetaData.getTableTypes`) for a simple user table.
    `String` | `tableTypeForView()` | Returns the name of the table type (as returned by `DatabaseMetaData.getTableTypes`) for a view table.
    `boolean` | `typeSupportsLength​(int type)` |
    `DbAdapter` | `unwrap()` | Allows the users to get access to the adapter decorated by a given adapter.

- - ### Method Detail

    - #### getBatchTerminator

          String getBatchTerminator()

      Returns a String used to terminate a batch in command-line tools. E.g. ";" on Oracle or "go" on Sybase.
      Since:
        1.0.4

    - #### getSelectTranslator

          SelectTranslator getSelectTranslator​(SelectQuery<?> query,
                                               EntityResolver entityResolver)

      Returns a SelectTranslator that works with the adapter target database.
      Since:
        4.0

    - #### getQualifierTranslator

          QualifierTranslator getQualifierTranslator​(QueryAssembler queryAssembler)

    - #### getAction

          SQLAction getAction​(Query query,
                              DataNode node)

      Returns an instance of SQLAction that should handle the query.
      Since:
        1.2

    - #### supportsUniqueConstraints

          boolean supportsUniqueConstraints()

      Returns true if a target database supports UNIQUE constraints.
      Since:
        1.1

    - #### supportsCatalogsOnReverseEngineering

          boolean supportsCatalogsOnReverseEngineering()

      Returns true if a target database supports catalogs on reverse engineering.
      Since:
        4.0

    - #### supportsGeneratedKeys

          boolean supportsGeneratedKeys()

      Returns true if a target database supports key autogeneration. This feature also requires JDBC3-compliant driver.
      Since:
        1.2

    - #### supportsBatchUpdates

          boolean supportsBatchUpdates()

      Returns `true` if the target database supports batch updates.

    - #### typeSupportsLength

          boolean typeSupportsLength​(int type)

    - #### dropTableStatements

          Collection<String> dropTableStatements​(DbEntity table)

      Returns a collection of SQL statements needed to drop a database table.
      Since:
        3.0

    - #### createTable

          String createTable​(DbEntity entity)

      Returns a SQL string that can be used to create database table corresponding to `entity` parameter.

    - #### createUniqueConstraint

          String createUniqueConstraint​(DbEntity source,
                                        Collection<DbAttribute> columns)

      Returns a DDL string to create a unique constraint over a set of columns, or null if the unique constraints are not supported.
      Since:
        1.1

    - #### createFkConstraint

          String createFkConstraint​(DbRelationship rel)

      Returns a SQL string that can be used to create a foreign key constraint for the relationship, or null if foreign keys are not supported.

    - #### externalTypesForJdbcType

          String[] externalTypesForJdbcType​(int type)

      Returns an array of RDBMS types that can be used with JDBC `type`. Valid JDBC types are defined in java.sql.Types.

    - #### getExtendedTypes

          ExtendedTypeMap getExtendedTypes()

      Returns a map of ExtendedTypes that is used to translate values between Java and JDBC layer.

    - #### getPkGenerator

          PkGenerator getPkGenerator()

      Returns primary key generator associated with this DbAdapter.

    - #### setPkGenerator

          void setPkGenerator​(PkGenerator pkGenerator)

      Set custom PK generator associated with this DbAdapter.
      Parameters:
        `pkGenerator` - to set
      Since:
        4.1

    - #### buildAttribute

          DbAttribute buildAttribute​(String name,
                                     String typeName,
                                     int type,
                                     int size,
                                     int scale,
                                     boolean allowNulls)

      Creates and returns a DbAttribute based on supplied parameters (usually obtained from database meta data).
      Parameters:
        `name` - database column name
        `typeName` - database specific type name, may be used as a hint to determine the right JDBC type.
        `type` - JDBC column type
        `size` - database column size (ignored if less than zero)
        `scale` - database column scale, i.e. the number of decimal digits (ignored if less than zero)
        `allowNulls` - database column nullable parameter

    - #### bindParameter

          void bindParameter​(PreparedStatement statement,
                             ParameterBinding parameterBinding)
                      throws SQLException,
                             Exception

      Binds an object value to PreparedStatement's parameter.
      Throws:
        `SQLException`
        `Exception`

    - #### tableTypeForTable

          String tableTypeForTable()

      Returns the name of the table type (as returned by `DatabaseMetaData.getTableTypes`) for a simple user table.

    - #### tableTypeForView

          String tableTypeForView()

      Returns the name of the table type (as returned by `DatabaseMetaData.getTableTypes`) for a view table.

    - #### createTableAppendColumn

          void createTableAppendColumn​(StringBuffer sqlBuffer,
                                       DbAttribute column)

      Append the column type part of a "create table" to the given `StringBuffer`
      Parameters:
        `sqlBuffer` - the `StringBuffer` to append the column type to
        `column` - the `DbAttribute` defining the column to append type for
      Since:
        3.0

    - #### getQuotingStrategy

          QuotingStrategy getQuotingStrategy()

      Returns SQL identifier quoting strategy object
      Since:
        4.0

    - #### unwrap

          DbAdapter unwrap()

      Allows the users to get access to the adapter decorated by a given adapter.
      Since:
        4.0

    - #### getEjbqlTranslatorFactory

          EJBQLTranslatorFactory getEjbqlTranslatorFactory()

      Returns a translator factory for EJBQL to SQL translation.
      Since:
        4.0

    - #### getSystemCatalogs

          List<String> getSystemCatalogs()

      Returns:
        list of system catalogs
      Since:
        4.1

    - #### getSystemSchemas

          List<String> getSystemSchemas()

      Returns:
        list of system schemas
      Since:
        4.1