com.blazebit.persistence.spi

Interface DbmsLimitHandler

public interface DbmsLimitHandler

Handler for applying SQL LIMIT and OFFSET to a query. Similar to Hibernates LimitHandler interface.

Since:

1.2.0

Author:

Christian Beikov

Method Summary

Modifier and Type	Method and Description
String	applySql(String sql, boolean isSubquery, Integer limit, Integer offset) Apply the LIMIT and OFFSET clause on the given SQL as parameters.
void	applySql(StringBuilder sqlSb, boolean isSubquery, String limit, String offset) Apply the LIMIT and OFFSET clause on the given SQL.
String	applySqlInlined(String sql, boolean isSubquery, Integer limit, Integer offset) Like applySql(String, boolean, Integer, Integer) but inlines the parameter values.
int	bindLimitParametersAtEndOfQuery(Integer limit, Integer offset, PreparedStatement statement, int index) Bind parameter values needed by the LIMIT clause after original SELECT statement.
int	bindLimitParametersAtStartOfQuery(Integer limit, Integer offset, PreparedStatement statement, int index) Bind parameter values needed by the LIMIT clause before original SELECT statement.
boolean	limitIncludesOffset() Returns whether the parameter value for OFFSET should be added to the value of LIMIT.
void	setMaxRows(Integer limit, Integer offset, PreparedStatement statement) Use JDBC API to limit the number of rows returned by the SQL query.
boolean	supportsLimit() Returns whether the dbms supports LIMIT via SQL.
boolean	supportsLimitOffset() Returns whether the dbms supports OFFSET via SQL.

Method Detail

supportsLimit

boolean supportsLimit()

Returns whether the dbms supports LIMIT via SQL.

Returns:

True if LIMIT is supported, otherwise false

supportsLimitOffset

boolean supportsLimitOffset()

Returns whether the dbms supports OFFSET via SQL.

Returns:

True if OFFSET is supported, otherwise false

limitIncludesOffset

boolean limitIncludesOffset()

Returns whether the parameter value for OFFSET should be added to the value of LIMIT.

Returns:

True if OFFSET should be added to LIMIT, otherwise false

applySql

String applySql(String sql,
                boolean isSubquery,
                Integer limit,
                Integer offset)

Apply the LIMIT and OFFSET clause on the given SQL as parameters. If parameters are not supported by the DBMS the values should be inlined.

Parameters:

sql - the sql query on which to apply

isSubquery - whether the query is a subquery

limit - the limit or null

offset - the offset or null

Returns:

Query statement with LIMIT clause applied.

applySqlInlined

String applySqlInlined(String sql,
                       boolean isSubquery,
                       Integer limit,
                       Integer offset)

Like applySql(String, boolean, Integer, Integer) but inlines the parameter values.

Parameters:

sql - the sql query on which to apply

isSubquery - whether the query is a subquery

limit - the limit or null

offset - the offset or null

Returns:

Query statement with LIMIT clause applied.

applySql

void applySql(StringBuilder sqlSb,
              boolean isSubquery,
              String limit,
              String offset)

Apply the LIMIT and OFFSET clause on the given SQL.

Parameters:

sqlSb - the string builder containing the sql query on which to apply

isSubquery - whether the query is a subquery

limit - the limit value or null

offset - the offset value or null

bindLimitParametersAtStartOfQuery

int bindLimitParametersAtStartOfQuery(Integer limit,
                                      Integer offset,
                                      PreparedStatement statement,
                                      int index)
                               throws SQLException

Bind parameter values needed by the LIMIT clause before original SELECT statement.

Parameters:

limit - the limit or null

offset - the offset or null

statement - the statement to which to apply parameters

index - the index on which to bind parameters

Returns:

The number of parameter values bound

Throws:

SQLException - Indicates problems binding parameter values

bindLimitParametersAtEndOfQuery

int bindLimitParametersAtEndOfQuery(Integer limit,
                                    Integer offset,
                                    PreparedStatement statement,
                                    int index)
                             throws SQLException

Bind parameter values needed by the LIMIT clause after original SELECT statement.

Parameters:

limit - the limit or null

offset - the offset or null

statement - the statement to which to apply parameters

index - the index on which to bind parameters

Returns:

The number of parameter values bound

Throws:

SQLException - Indicates problems binding parameter values

setMaxRows

void setMaxRows(Integer limit,
                Integer offset,
                PreparedStatement statement)
         throws SQLException

Use JDBC API to limit the number of rows returned by the SQL query. Typically handlers that do not support LIMIT clause should implement this method.

Parameters:

limit - the limit or null

offset - the offset or null

statement - the statement on which to apply max rows

Throws:

SQLException - Indicates problems while limiting maximum rows returned