public Class PostgreSQLDialect

Overrides org.hibernate.dialect.Dialect.bindLimitParametersInReverseOrder.

Doc from org.hibernate.dialect.Dialect.bindLimitParametersInReverseOrder.

ANSI SQL defines the LIMIT clause to be in the form LIMIT offset, limit. Does this dialect require us to bind the parameters in reverse order?

Returns:boolean

true if the correct order is limit, offset

Overrides org.hibernate.dialect.Dialect.dropConstraints.

Doc from org.hibernate.dialect.Dialect.dropConstraints.

Do we need to drop constraints before dropping tables in this dialect?

Returns:boolean

True if constraints must be dropped prior to dropping the table; false otherwise.

Overrides org.hibernate.dialect.Dialect.getAddColumnString.

Doc from org.hibernate.dialect.Dialect.getAddColumnString.

The syntax used to add a column to a table (optional).

Returns:String

The "add column" fragment.

Overrides org.hibernate.dialect.Dialect.getCascadeConstraintsString.

Doc from org.hibernate.dialect.Dialect.getCascadeConstraintsString.

Completely optional cascading drop clause

Returns:String

String

Overrides org.hibernate.dialect.Dialect.getCreateSequenceString.

Doc from org.hibernate.dialect.Dialect.getCreateSequenceString.

Typically dialects which support sequences can create a sequence with a single command. This is convenience form of getCreateSequenceStrings to help facilitate that.

Dialects which support sequences and can create a sequence in a single command need *only* override this method. Dialects which support sequences but require multiple commands to create a sequence should instead override getCreateSequenceStrings.

Parameters

sequenceName:String

The name of the sequence

Returns:String

The sequence creation command

Overrides org.hibernate.dialect.Dialect.getCreateTemporaryTablePostfix.

Doc from org.hibernate.dialect.Dialect.getCreateTemporaryTablePostfix.

Get any fragments needing to be postfixed to the command for temporary table creation.

Returns:String

Any required postfix.

Overrides org.hibernate.dialect.Dialect.getCreateTemporaryTableString.

Doc from org.hibernate.dialect.Dialect.getCreateTemporaryTableString.

Command used to create a temporary table.

Returns:String

The command used to create a temporary table.

Overrides org.hibernate.dialect.Dialect.getCurrentTimestampSelectString.

Doc from org.hibernate.dialect.Dialect.getCurrentTimestampSelectString.

Retrieve the command used to retrieve the current timestamp from the database.

Returns:String

The command.

Overrides org.hibernate.dialect.Dialect.getDropSequenceString.

Doc from org.hibernate.dialect.Dialect.getDropSequenceString.

Typically dialects which support sequences can drop a sequence with a single command. This is convenience form of getDropSequenceStrings to help facilitate that.

Dialects which support sequences and can drop a sequence in a single command need *only* override this method. Dialects which support sequences but require multiple commands to drop a sequence should instead override getDropSequenceStrings.

Parameters

sequenceName:String

The name of the sequence

Returns:String

The sequence drop commands

Overrides org.hibernate.dialect.Dialect.getForUpdateString.

Doc from org.hibernate.dialect.Dialect.getForUpdateString.

Get the FOR UPDATE OF column_list fragment appropriate for this dialect given the aliases of the columns to be write locked.

Parameters

aliases:String

The columns to be write locked.

Returns:String

The appropriate FOR UPDATE OF column_list clause string.

Overrides org.hibernate.dialect.Dialect.getForUpdateString.

Doc from org.hibernate.dialect.Dialect.getForUpdateString.

Get the string to append to SELECT statements to acquire locks for this dialect.

Returns:String

The appropriate FOR UPDATE clause string.

Overrides org.hibernate.dialect.Dialect.getIdentityColumnString.

Doc from org.hibernate.dialect.Dialect.getIdentityColumnString.

The syntax used during DDL to define a column as being an IDENTITY of a particular type.

Parameters

type:int

The java.sql.Types type code.

Returns:String

The appropriate DDL fragment.

Overrides org.hibernate.dialect.Dialect.getIdentitySelectString.

Doc from org.hibernate.dialect.Dialect.getIdentitySelectString.

Get the select command to use to retrieve the last generated IDENTITY value for a particular table

Parameters

table:String

The table into which the insert was done

column:String

The PK column.

type:int

The java.sql.Types type code.

Returns:String

The appropriate select command

Overrides org.hibernate.dialect.Dialect.getLimitString.

Doc from org.hibernate.dialect.Dialect.getLimitString.

Apply s limit clause to the query.

Typically dialects utilize variable limit clauses when they support limits. Thus, when building the select command we do not actually need to know the limit or the offest since we will just be using placeholders.

Here we do still pass along whether or not an offset was specified so that dialects not supporting offsets can generate proper exceptions. In general, dialects will override one or the other of this method and getLimitString(String, int, int).

Parameters

sql:String

The query to which to apply the limit.

hasOffset:boolean

Is the query requesting an offset?

Returns:String

the modified SQL

Overrides org.hibernate.dialect.Dialect.getNativeIdentifierGeneratorClass.

Doc from org.hibernate.dialect.Dialect.getNativeIdentifierGeneratorClass.

The class (which implements org.hibernate.id.IdentifierGenerator) which acts as this dialects native generation strategy.

Comes into play whenever the user specifies the native generator.

Returns:Class<T>

The native generator class.

Overrides org.hibernate.dialect.Dialect.getNoColumnsInsertString.

Doc from org.hibernate.dialect.Dialect.getNoColumnsInsertString.

The fragment used to insert a row without specifying any column values. This is not possible on some databases.

Returns:String

The appropriate empty values clause.

Overrides org.hibernate.dialect.Dialect.getQuerySequencesString.

Doc from org.hibernate.dialect.Dialect.getQuerySequencesString.

Get the select command used retrieve the names of all sequences.

Returns:String

The select command; or null if sequences are not supported.

Overrides org.hibernate.dialect.Dialect.getReadLockString.

Doc from org.hibernate.dialect.Dialect.getReadLockString.

Get the string to append to SELECT statements to acquire WRITE locks for this dialect. Location of the of the returned string is treated the same as getForUpdateString.

Parameters

timeout:int

in milliseconds, -1 for indefinite wait and 0 for no wait.

Returns:String

The appropriate LOCK clause string.

Overrides org.hibernate.dialect.Dialect.getResultSet.

Doc from org.hibernate.dialect.Dialect.getResultSet.

Given a callable statement previously processed by registerResultSetOutParameter, extract the java.sql.ResultSet from the OUT parameter.

Parameters

ps:CallableStatement

The callable statement.

Returns:ResultSet

The extracted result set.

Exceptions

SQLException:

Indicates problems extracting the result set.

Overrides org.hibernate.dialect.Dialect.getSelectClauseNullString.

Workaround for postgres bug #1453

Parameters

sqlType:int

Doc from org.hibernate.dialect.Dialect.getSelectClauseNullString.

The java.sql.Types type code.

Returns:String

Doc from org.hibernate.dialect.Dialect.getSelectClauseNullString.

The appropriate select clause value fragment.

Overrides org.hibernate.dialect.Dialect.getSelectSequenceNextValString.

Doc from org.hibernate.dialect.Dialect.getSelectSequenceNextValString.

Generate the select expression fragment that will retrieve the next value of a sequence as part of another (typically DML) statement.

This differs from getSequenceNextValString(String) in that this should return an expression usable within another statement.

Parameters

sequenceName:String

the name of the sequence

Returns:String

The "nextval" fragment.

Overrides org.hibernate.dialect.Dialect.getSequenceNextValString.

Doc from org.hibernate.dialect.Dialect.getSequenceNextValString.

Generate the appropriate select statement to to retrieve the next value of a sequence.

This should be a "stand alone" select statement.

Parameters

sequenceName:String

the name of the sequence

Returns:String

String The "nextval" select string.

Overrides org.hibernate.dialect.Dialect.getViolatedConstraintNameExtracter.

Overrides org.hibernate.dialect.Dialect.getWriteLockString.

Doc from org.hibernate.dialect.Dialect.getWriteLockString.

Get the string to append to SELECT statements to acquire WRITE locks for this dialect. Location of the of the returned string is treated the same as getForUpdateString.

Parameters

timeout:int

in milliseconds, -1 for indefinite wait and 0 for no wait.

Returns:String

The appropriate LOCK clause string.

Overrides org.hibernate.dialect.Dialect.hasDataTypeInIdentityColumn.

Doc from org.hibernate.dialect.Dialect.hasDataTypeInIdentityColumn.

Whether this dialect have an Identity clause added to the data type or a completely separate identity data type

Returns:boolean

boolean

Overrides org.hibernate.dialect.Dialect.isCurrentTimestampSelectStringCallable.

Doc from org.hibernate.dialect.Dialect.isCurrentTimestampSelectStringCallable.

Should the value returned by getCurrentTimestampSelectString be treated as callable. Typically this indicates that JDBC escape syntax is being used...

Returns:boolean

True if the getCurrentTimestampSelectString return is callable; false otherwise.

Overrides org.hibernate.dialect.Dialect.registerResultSetOutParameter.

Doc from org.hibernate.dialect.Dialect.registerResultSetOutParameter.

Registers an OUT parameter which will be returning a java.sql.ResultSet. How this is accomplished varies greatly from DB to DB, hence its inclusion (along with getResultSet) here.

Parameters

statement:CallableStatement

The callable statement.

col:int

The bind position at which to register the OUT param.

Returns:int

The number of (contiguous) bind positions used.

Exceptions

SQLException:

Indicates problems registering the OUT param.

Overrides org.hibernate.dialect.Dialect.supportsCommentOn.

Overrides org.hibernate.dialect.Dialect.supportsCurrentTimestampSelection.

Doc from org.hibernate.dialect.Dialect.supportsCurrentTimestampSelection.

Does this dialect support a way to retrieve the database's current timestamp value?

Returns:boolean

True if the current timestamp can be retrieved; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsEmptyInList.

Doc from org.hibernate.dialect.Dialect.supportsEmptyInList.

Does this dialect support empty IN lists?

For example, is [where XYZ in ()] a supported construct?

Returns:boolean

True if empty in lists are supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsExpectedLobUsagePattern.

Doc from org.hibernate.dialect.Dialect.supportsExpectedLobUsagePattern.

Expected LOB usage pattern is such that I can perform an insert via prepared statement with a parameter binding for a LOB value without crazy casting to JDBC driver implementation-specific classes...

Part of the trickiness here is the fact that this is largely driver dependent. For example, Oracle (which is notoriously bad with LOB support in their drivers historically) actually does a pretty good job with LOB support as of the 10.2.x versions of their drivers...

Returns:boolean

True if normal LOB usage patterns can be used with this driver; false if driver-specific hookiness needs to be applied.

Annotations

@Override

Overrides org.hibernate.dialect.Dialect.supportsIdentityColumns.

Doc from org.hibernate.dialect.Dialect.supportsIdentityColumns.

Does this dialect support identity column key generation?

Returns:boolean

True if IDENTITY columns are supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsLimit.

Doc from org.hibernate.dialect.Dialect.supportsLimit.

Does this dialect support some form of limiting query results via a SQL clause?

Returns:boolean

True if this dialect supports some form of LIMIT.

Overrides org.hibernate.dialect.Dialect.supportsLobValueChangePropogation.

Doc from org.hibernate.dialect.Dialect.supportsLobValueChangePropogation.

Does the dialect support propagating changes to LOB values back to the database? Talking about mutating the internal value of the locator as opposed to supplying a new locator instance...

For BLOBs, the internal value might be changed by: java.sql.Blob#setBinaryStream, java.sql.Blob#setBytes(long, byte[]), java.sql.Blob#setBytes(long, byte[], int, int), or java.sql.Blob#truncate(long).

For CLOBs, the internal value might be changed by: java.sql.Clob#setAsciiStream(long), java.sql.Clob#setCharacterStream(long), java.sql.Clob#setString(long, String), java.sql.Clob#setString(long, String, int, int), or java.sql.Clob#truncate(long).

NOTE : I do not know the correct answer currently for databases which (1) are not part of the cruise control process or (2) do not supportsExpectedLobUsagePattern.

Returns:boolean

True if the changes are propagated back to the database; false otherwise.

Annotations

@Override

Overrides org.hibernate.dialect.Dialect.supportsOuterJoinForUpdate.

Doc from org.hibernate.dialect.Dialect.supportsOuterJoinForUpdate.

Does this dialect support FOR UPDATE in conjunction with outer joined rows?

Returns:boolean

True if outer joined rows can be locked via FOR UPDATE.

Overrides org.hibernate.dialect.Dialect.supportsPooledSequences.

Doc from org.hibernate.dialect.Dialect.supportsPooledSequences.

Does this dialect support "pooled" sequences. Not aware of a better name for this. Essentially can we specify the initial and increment values?

Returns:boolean

True if such "pooled" sequences are supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsSequences.

Doc from org.hibernate.dialect.Dialect.supportsSequences.

Does this dialect support sequences?

Returns:boolean

True if sequences supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsTemporaryTables.

Doc from org.hibernate.dialect.Dialect.supportsTemporaryTables.

Does this dialect support temporary tables?

Returns:boolean

True if temp tables are supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsTupleDistinctCounts.

Doc from org.hibernate.dialect.Dialect.supportsTupleDistinctCounts.

Does this dialect support `count(distinct a,b)`?

Returns:boolean

True if the database supports counting disintct tuples; false otherwise.

Overrides org.hibernate.dialect.Dialect.supportsUnboundedLobLocatorMaterialization.

Doc from org.hibernate.dialect.Dialect.supportsUnboundedLobLocatorMaterialization.

Is it supported to materialize a LOB locator outside the transaction in which it was created?

Again, part of the trickiness here is the fact that this is largely driver dependent.

Returns:boolean

True if unbounded materialization is supported; false otherwise.

Annotations

@Override

Overrides org.hibernate.dialect.Dialect.supportsUnionAll.

Doc from org.hibernate.dialect.Dialect.supportsUnionAll.

Does this dialect support UNION ALL, which is generally a faster variant of UNION?

Returns:boolean

True if UNION ALL is supported; false otherwise.

Overrides org.hibernate.dialect.Dialect.toBooleanValueString.

Doc from org.hibernate.dialect.Dialect.toBooleanValueString.

The SQL literal value to which this database maps boolean values.

Parameters

bool:boolean

The boolean value

Returns:String

The appropriate SQL literal.

Overrides org.hibernate.dialect.Dialect.useInputStreamToInsertBlob.

Doc from org.hibernate.dialect.Dialect.useInputStreamToInsertBlob.

Should LOBs (both BLOB and CLOB) be bound using stream operations (i.e. java.sql.PreparedStatement#setBinaryStream).

Returns:boolean

True if BLOBs and CLOBs should be bound using stream operations.