org.apache.flink.connector.jdbc.dialect

Class AbstractDialect

java.lang.Object

org.apache.flink.connector.jdbc.dialect.AbstractDialect

All Implemented Interfaces:

Serializable, JdbcDialect

Direct Known Subclasses:

DerbyDialect, MySqlDialect, OracleDialect, PostgresDialect, SqlServerDialect

@PublicEvolving
public abstract class AbstractDialect
extends Object
implements JdbcDialect

Base class for JdbcDialects that implements basic data type validation and the construction of basic INSERT, UPDATE, DELETE, and SELECT statements.

Implementors should be careful to check the default SQL statements are performant for their specific dialect and override them if necessary.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AbstractDialect.Range A range from [min,max] where min <= max.

Constructor Summary

Constructors

Constructor and Description
AbstractDialect()

Method Summary

Modifier and Type	Method and Description
Optional<AbstractDialect.Range>	decimalPrecisionRange()
String	getDeleteStatement(String tableName, String[] conditionFields) A simple single row DELETE statement.
String	getInsertIntoStatement(String tableName, String[] fieldNames) A simple INSERT INTO statement.
String	getRowExistsStatement(String tableName, String[] conditionFields) A simple SELECT statement that checks for the existence of a single row.
String	getSelectFromStatement(String tableName, String[] selectFields, String[] conditionFields) A simple SELECT statement.
String	getUpdateStatement(String tableName, String[] fieldNames, String[] conditionFields) A simple single row UPDATE statement.
abstract Set<org.apache.flink.table.types.logical.LogicalTypeRoot>	supportedTypes() Defines the set of supported types for the dialect.
Optional<AbstractDialect.Range>	timestampPrecisionRange()
void	validate(org.apache.flink.table.types.logical.RowType rowType) Check if this dialect instance support a specific data type in table schema.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.flink.connector.jdbc.dialect.JdbcDialect

appendDefaultUrlProperties, defaultDriverName, dialectName, getLimitClause, getRowConverter, getUpsertStatement, quoteIdentifier

Constructor Detail

AbstractDialect

public AbstractDialect()

Method Detail

validate

public void validate(org.apache.flink.table.types.logical.RowType rowType)
              throws org.apache.flink.table.api.ValidationException

Description copied from interface: JdbcDialect

Check if this dialect instance support a specific data type in table schema.

Specified by:

validate in interface JdbcDialect

Parameters:

rowType - the physical table datatype of a row in the database table.

Throws:

org.apache.flink.table.api.ValidationException - in case of the table schema contains unsupported type.

getInsertIntoStatement

public String getInsertIntoStatement(String tableName,
                                     String[] fieldNames)

A simple INSERT INTO statement.

 INSERT INTO table_name (column_name [, ...])
 VALUES (value [, ...])
 

Specified by:

getInsertIntoStatement in interface JdbcDialect

Returns:

the dialects INSERT INTO statement.

getUpdateStatement

public String getUpdateStatement(String tableName,
                                 String[] fieldNames,
                                 String[] conditionFields)

A simple single row UPDATE statement.

 UPDATE table_name
 SET col = val [, ...]
 WHERE cond [AND ...]
 

Specified by:

getUpdateStatement in interface JdbcDialect

Returns:

A single row update statement.

getDeleteStatement

public String getDeleteStatement(String tableName,
                                 String[] conditionFields)

A simple single row DELETE statement.

 DELETE FROM table_name
 WHERE cond [AND ...]
 

Specified by:

getDeleteStatement in interface JdbcDialect

Returns:

A single row delete statement.

getSelectFromStatement

public String getSelectFromStatement(String tableName,
                                     String[] selectFields,
                                     String[] conditionFields)

A simple SELECT statement.

 SELECT expression [, ...]
 FROM table_name
 WHERE cond [AND ...]
 

Specified by:

getSelectFromStatement in interface JdbcDialect

Returns:

A select statement.

getRowExistsStatement

public String getRowExistsStatement(String tableName,
                                    String[] conditionFields)

A simple SELECT statement that checks for the existence of a single row.

 SELECT 1
 FROM table_name
 WHERE cond [AND ...]
 

Specified by:

getRowExistsStatement in interface JdbcDialect

timestampPrecisionRange

public Optional<AbstractDialect.Range> timestampPrecisionRange()

Returns:

The inclusive range [min,max] of supported precisions for TimestampType columns. None if timestamp type is not supported.

decimalPrecisionRange

public Optional<AbstractDialect.Range> decimalPrecisionRange()

Returns:

The inclusive range [min,max] of supported precisions for DecimalType columns. None if decimal type is not supported.

supportedTypes

public abstract Set<org.apache.flink.table.types.logical.LogicalTypeRoot> supportedTypes()

Defines the set of supported types for the dialect. If the dialect supports DECIMAL or TIMESTAMP types, be sure to override decimalPrecisionRange() and timestampPrecisionRange() respectively.

Returns:

a set of logical type roots.