org.exolab.castor.persist.spi

Interface QueryExpression

All Known Implementing Classes:

DB2QueryExpression, DerbyQueryExpression, HsqlQueryExpression, InformixQueryExpression, InstantDBQueryExpression, InterbaseQueryExpression, JDBCQueryExpression, MySQLQueryExpression, OracleQueryExpression, PointbaseQueryExpression, PostgreSQLQueryExpression, ProgressQueryExpression, SapDbQueryExpression, SQLServerQueryExpression, SybaseQueryExpression

public interface QueryExpression

Defines the interface for a query expression. The query expression object is used to construct queries including parameters, conditions and joins, and generates the SQL statement for the underlying database.

A query experession object is created for each unique query, populated with the query parameters and the SQL statement is obtained from it at the proper time.

A query expression is generated from PersistenceFactory, see this interface for information on how to configure it. The operators defined in this interface are part of SQL 92 and the supported OQL syntax and are expected to be supported by all query expressions.

Version:

$Revision: 5951 $ $Date: 2005-03-05 06:42:06 -0700 (Sat, 05 Mar 2005) $

Author:

Assaf Arkin

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	OpBetween Between operator.
static java.lang.String	OpBetweenAnd Between and operator.
static java.lang.String	OpEquals Equality operator.
static java.lang.String	OpGreater Greater then operator.
static java.lang.String	OpGreaterEquals Greater then or equals operator.
static java.lang.String	OpLess Less then operator.
static java.lang.String	OpLessEquals Less then or equals operator.
static java.lang.String	OpLike Like operator.
static java.lang.String	OpNotEquals Inequality operator.
static java.lang.String	OpNotLike Not like operator.

Method Summary

Modifier and Type	Method and Description
void	addColumn(java.lang.String tableName, java.lang.String columnName) Add a column used in the query.
void	addCondition(java.lang.String tableName, java.lang.String columnName, java.lang.String condOp, java.lang.String value) Add a condition.
void	addInnerJoin(java.lang.String leftTable, java.lang.String[] leftColumn, java.lang.String rightTable, java.lang.String[] rightColumn) Add an inner join
void	addInnerJoin(java.lang.String leftTable, java.lang.String[] leftColumn, java.lang.String leftTableAlias, java.lang.String rightTable, java.lang.String[] rightColumn, java.lang.String rightTableAlias) Add an inner join with an aliases for the tables
void	addInnerJoin(java.lang.String leftTable, java.lang.String leftColumn, java.lang.String rightTable, java.lang.String rightColumn) Add an inner join.
void	addInnerJoin(java.lang.String leftTable, java.lang.String leftColumn, java.lang.String leftTableAlias, java.lang.String rightTable, java.lang.String rightColumn, java.lang.String rightTableAlias) Add an inner join with an aliases for the tables
void	addLimitClause(java.lang.String limitClause) Adds an limit clause.
void	addOffsetClause(java.lang.String offsetClause) Adds an offset clause.
void	addOrderClause(java.lang.String orderClause) Adds an order by clause.
void	addOuterJoin(java.lang.String leftTable, java.lang.String[] leftColumn, java.lang.String rightTable, java.lang.String[] rightColumn)
void	addOuterJoin(java.lang.String leftTable, java.lang.String[] leftColumn, java.lang.String rightTable, java.lang.String[] rightColumn, java.lang.String rightTableAlias)
void	addOuterJoin(java.lang.String leftTable, java.lang.String leftColumn, java.lang.String rightTable, java.lang.String rightColumn) Add an outer join.
void	addOuterJoin(java.lang.String leftTable, java.lang.String leftColumn, java.lang.String rightTable, java.lang.String rightColumn, java.lang.String rightTableAlias) Add an outer join.
void	addParameter(java.lang.String tableName, java.lang.String columnName, java.lang.String condOp) Add a query paramater.
void	addSelect(java.lang.String selectClause) Add an entire select clause to the query with one call.
void	addTable(java.lang.String tableName) Add a table to the from clause.
void	addTable(java.lang.String tableName, java.lang.String tableAlias) Add a table with an alias to the from clause.
void	addWhereClause(java.lang.String whereClause) Adds a where clause.
java.lang.Object	clone() Returns a clone of the query expression that can be further modified.
java.lang.String	encodeColumn(java.lang.String tableName, java.lang.String columnName) Encode a TableColumn for use in expressions
java.lang.String	getStatement(boolean writeLock) Return the query expression as an SQL statement.
boolean	isLimitClauseSupported() Indicates whether a RDBMS supports LIMIT clauses.
boolean	isOffsetClauseSupported() Indicates whether a RDBMS supports OFFSET clauses.
void	setDbMetaInfo(DbMetaInfo dbInfo) Store database meta information
void	setDistinct(boolean distinct) Set the query to be distinct.

Field Detail

OpEquals

static final java.lang.String OpEquals

Equality operator. (=)

See Also:

Constant Field Values

OpNotEquals

static final java.lang.String OpNotEquals

Inequality operator. (<>)

See Also:

Constant Field Values

OpGreater

static final java.lang.String OpGreater

Greater then operator. (>)

See Also:

Constant Field Values

OpGreaterEquals

static final java.lang.String OpGreaterEquals

Greater then or equals operator. (>=)

See Also:

Constant Field Values

OpLess

static final java.lang.String OpLess

Less then operator. (<)

See Also:

Constant Field Values

OpLessEquals

static final java.lang.String OpLessEquals

Less then or equals operator. (<=)

See Also:

Constant Field Values

OpLike

static final java.lang.String OpLike

Like operator. (LIKE)

See Also:

Constant Field Values

OpNotLike

static final java.lang.String OpNotLike

Not like operator. (NOT LIKE)

See Also:

Constant Field Values

OpBetween

static final java.lang.String OpBetween

Between operator. (BETWEEN)

See Also:

OpBetweenAnd, Constant Field Values

OpBetweenAnd

static final java.lang.String OpBetweenAnd

Between and operator. (AND)

See Also:

OpBetween, Constant Field Values

Method Detail

addColumn

void addColumn(java.lang.String tableName,
               java.lang.String columnName)

Add a column used in the query. Columns must be retrieved in the same order in which they were added to the query.

Parameters:

tableName - The table name

columnName - The column name

addSelect

void addSelect(java.lang.String selectClause)

Add an entire select clause to the query with one call. The caller is responsible for making sure that all mentioned tables are included in the from clause.

Parameters:

selectClause - The entire sql select clause without the word SELECT

setDistinct

void setDistinct(boolean distinct)

Set the query to be distinct. No two rows which are the same will be returned.

Parameters:

distinct - If the query should include DISTINCT in the SQL select.

addTable

void addTable(java.lang.String tableName)

Add a table to the from clause.

Parameters:

tableName - The name of the table to add to the select clause

addTable

void addTable(java.lang.String tableName,
              java.lang.String tableAlias)

Add a table with an alias to the from clause.

Parameters:

tableName - The name of the table to add to the select clause

tableAlias - The name of the alias under which the where clauses will access it

addParameter

void addParameter(java.lang.String tableName,
                  java.lang.String columnName,
                  java.lang.String condOp)

Add a query paramater.

Parameters:

tableName - The table name

columnName - The column name

condOp - The conditional operation

addCondition

void addCondition(java.lang.String tableName,
                  java.lang.String columnName,
                  java.lang.String condOp,
                  java.lang.String value)

Add a condition.

Parameters:

tableName - The table name

columnName - The column name

condOp - The conditional operation

value - The conditional value

encodeColumn

java.lang.String encodeColumn(java.lang.String tableName,
                              java.lang.String columnName)

Encode a TableColumn for use in expressions

Parameters:

tableName - The table name

columnName - The column name

addWhereClause

void addWhereClause(java.lang.String whereClause)

Adds a where clause. Caller is responsible for making sure all tables mentioned in the where clause are included in the fromClause.

Parameters:

whereClause - The WHERE clause to add (without the word WHERE).

addOrderClause

void addOrderClause(java.lang.String orderClause)

Adds an order by clause. Caller is responsible for making sure all tables mentioned in the order by clause are included in the fromClause.

Parameters:

orderClause - The ORDER BY clause to add (without the words ORDER BY).

addLimitClause

void addLimitClause(java.lang.String limitClause)
             throws SyntaxNotSupportedException

Adds an limit clause.

Parameters:

limitClause - The LIMIT clause to add (without the word LIMIT).

Throws:

SyntaxNotSupportedException - If the LIMIT clause is not supported by the RDBMS.

addOffsetClause

void addOffsetClause(java.lang.String offsetClause)
              throws SyntaxNotSupportedException

Adds an offset clause.

Parameters:

offsetClause - The OFFSET clause to add (without the word OFFSET).

Throws:

SyntaxNotSupportedException - If the OFFSET clause is not supported by the RDBMS.

addInnerJoin

void addInnerJoin(java.lang.String leftTable,
                  java.lang.String leftColumn,
                  java.lang.String rightTable,
                  java.lang.String rightColumn)

Add an inner join.

Parameters:

leftTable - The table name on the left side

leftColumn - The column name on the left side

rightTable - The table name on the right side

rightColumn - The column name on the right side

addInnerJoin

void addInnerJoin(java.lang.String leftTable,
                  java.lang.String leftColumn,
                  java.lang.String leftTableAlias,
                  java.lang.String rightTable,
                  java.lang.String rightColumn,
                  java.lang.String rightTableAlias)

Add an inner join with an aliases for the tables

Parameters:

leftTable - The table name on the left side

leftColumn - The column name on the left side

leftTableAlias - The alias name to use for the table on the left side

rightTable - The table name on the right side

rightColumn - The column name on the right side

rightTableAlias - The alias name to use for the table on the right side

addOuterJoin

void addOuterJoin(java.lang.String leftTable,
                  java.lang.String leftColumn,
                  java.lang.String rightTable,
                  java.lang.String rightColumn)

Add an outer join. May use an inner join if outer joins are not supported.

Parameters:

leftTable - The table name on the left side

leftColumn - The column name on the left side

rightTable - The table name on the right side

rightColumn - The column name on the right side

addOuterJoin

void addOuterJoin(java.lang.String leftTable,
                  java.lang.String leftColumn,
                  java.lang.String rightTable,
                  java.lang.String rightColumn,
                  java.lang.String rightTableAlias)

Add an outer join. May use an inner join if outer joins are not supported.

Parameters:

leftTable - The table name on the left side

leftColumn - The column name on the left side

rightTable - The table name on the right side

rightColumn - The column name on the right side

rightTableAlias - The alias name to use for the table on the right side

addInnerJoin

void addInnerJoin(java.lang.String leftTable,
                  java.lang.String[] leftColumn,
                  java.lang.String rightTable,
                  java.lang.String[] rightColumn)

Add an inner join

Parameters:

leftTable - The table name on the left side

leftColumn - The column names on the left side

rightTable - The table name on the right side

rightColumn - The column names on the right side

addInnerJoin

void addInnerJoin(java.lang.String leftTable,
                  java.lang.String[] leftColumn,
                  java.lang.String leftTableAlias,
                  java.lang.String rightTable,
                  java.lang.String[] rightColumn,
                  java.lang.String rightTableAlias)

Add an inner join with an aliases for the tables

Parameters:

leftTable - The table name on the left side

leftColumn - The column names on the left side

leftTableAlias - The alias name to use for the table on the left side

rightTable - The table name on the right side

rightColumn - The column names on the right side

rightTableAlias - The alias name to use for the table on the right side

addOuterJoin

void addOuterJoin(java.lang.String leftTable,
                  java.lang.String[] leftColumn,
                  java.lang.String rightTable,
                  java.lang.String[] rightColumn)

addOuterJoin

void addOuterJoin(java.lang.String leftTable,
                  java.lang.String[] leftColumn,
                  java.lang.String rightTable,
                  java.lang.String[] rightColumn,
                  java.lang.String rightTableAlias)

getStatement

java.lang.String getStatement(boolean writeLock)
                       throws QueryException

Return the query expression as an SQL statement. The resulting SQL is fed directly to a JDBC statement. writeLock is true if the query must obtain a write lock on the queried table.

Parameters:

writeLock - True if a write lock is required

Returns:

The SQL statement

Throws:

QueryException - The query cannot be constructed for this engine

clone

java.lang.Object clone()

Returns a clone of the query expression that can be further modified.

isLimitClauseSupported

boolean isLimitClauseSupported()

Indicates whether a RDBMS supports LIMIT clauses.

Returns:

True if a LIMIT clause is supported.

isOffsetClauseSupported

boolean isOffsetClauseSupported()

Indicates whether a RDBMS supports OFFSET clauses.

Returns:

True if an OFFSET clause is supported.

setDbMetaInfo

void setDbMetaInfo(DbMetaInfo dbInfo)

Store database meta information

Parameters:

dbInfo - DbMetaInfo instance