public Class InformixDialect

Creates new InformixDialect instance. Sets up the JDBC / Informix type mappings.

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.getAddForeignKeyConstraintString.

The syntax used to add a foreign key constraint to a table. Informix constraint name must be at the end.

Parameters

constraintName:String

Doc from org.hibernate.dialect.Dialect.getAddForeignKeyConstraintString.

The FK constraint name.

foreignKey:String[]

Doc from org.hibernate.dialect.Dialect.getAddForeignKeyConstraintString.

The names of the columns comprising the FK

referencedTable:String

Doc from org.hibernate.dialect.Dialect.getAddForeignKeyConstraintString.

The table referenced by the FK

primaryKey:String[]

Doc from org.hibernate.dialect.Dialect.getAddForeignKeyConstraintString.

The explicit columns in the referencedTable referenced by this FK.

referencesPrimaryKey:boolean

Doc from org.hibernate.dialect.Dialect.getAddForeignKeyConstraintString.

if false, constraint should be explicit about which column names the constraint refers to

Returns:String

String

Overrides org.hibernate.dialect.Dialect.getAddPrimaryKeyConstraintString.

The syntax used to add a primary key constraint to a table. Informix constraint name must be at the end.

Parameters

constraintName:String

Doc from org.hibernate.dialect.Dialect.getAddPrimaryKeyConstraintString.

The name of the PK constraint.

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.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.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.

Exceptions

MappingException:

If IDENTITY generation is not supported.

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

Exceptions

MappingException:

If IDENTITY generation is not supported.

Overrides org.hibernate.dialect.Dialect.getLimitString.

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

Given a limit and an offset, apply the limit clause to the query.

Parameters

querySelect:String

The query to which to apply the limit.

offset:int

The offset of the limit

limit:int

The limit of the limit ;)

Returns:String

The modified query statement with the limit applied.

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.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.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.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.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.supportsLimitOffset.

Doc from org.hibernate.dialect.Dialect.supportsLimitOffset.

Does this dialect's LIMIT support (if any) additionally support specifying an offset?

Returns:boolean

True if the dialect supports an offset within the limit support.

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.supportsVariableLimit.

Doc from org.hibernate.dialect.Dialect.supportsVariableLimit.

Does this dialect support bind variables (i.e., prepared statement parameters) for its limit/offset?

Returns:boolean

True if bind variables can be used; false otherwise.

Overrides org.hibernate.dialect.Dialect.useMaxForLimit.

Doc from org.hibernate.dialect.Dialect.useMaxForLimit.

Does the LIMIT clause take a "maximum" row number instead of a total number of returned rows?

This is easiest understood via an example. Consider you have a table with 20 rows, but you only want to retrieve rows number 11 through 20. Generally, a limit with offset would say that the offset = 11 and the limit = 10 (we only want 10 rows at a time); this is specifying the total number of returned rows. Some dialects require that we instead specify offset = 11 and limit = 20, where 20 is the "last" row we want relative to offset (i.e. total number of rows = 20 - 11 = 9)

So essentially, is limit relative from offset? Or is limit absolute?

Returns:boolean

True if limit is relative from offset; false otherwise.