QueryExpression (Castor 1.3.2 API)

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: 8459 $ $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 String`	`OP_BETWEEN` Between operator.
`static String`	`OP_BETWEEN_AND` Between and operator.
`static String`	`OP_EQUALS` Equality operator.
`static String`	`OP_GREATER` Greater then operator.
`static String`	`OP_GREATER_EQUALS` Greater then or equals operator.
`static String`	`OP_LESS` Less then operator.
`static String`	`OP_LESS_EQUALS` Less then or equals operator.
`static String`	`OP_LIKE` Like operator.
`static String`	`OP_NOT_EQUALS` Inequality operator.
`static String`	`OP_NOT_LIKE` Not like operator.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addColumn(String tableName, String columnName)` Add a column used in the query.
`void`	`addCondition(String tableName, String columnName, String condOp, String value)` Add a condition.
`void`	`addInnerJoin(String leftTable, String[] leftColumn, String leftTableAlias, String rightTable, String[] rightColumn, String rightTableAlias)` Add an inner join with an aliases for the tables.
`void`	`addLimitClause(String limitClause)` Adds an limit clause.
`void`	`addOffsetClause(String offsetClause)` Adds an offset clause.
`void`	`addOrderClause(String orderClause)` Adds an order by clause.
`void`	`addOuterJoin(String leftTable, String[] leftColumn, String rightTable, String[] rightColumn, String rightTableAlias)` Add an outer join.
`void`	`addParameter(String tableName, String columnName, String condOp)` Add a query paramater.
`void`	`addSelect(String selectClause)` Add an entire select clause to the query with one call.
`void`	`addTable(String tableName, String tableAlias)` Add a table with an alias to the from clause.
`void`	`addWhereClause(String whereClause)` Adds a where clause.
`Object`	`clone()` Returns a clone of the query expression that can be further modified.
`String`	`encodeColumn(String tableName, String columnName)` Encode a TableColumn for use in expressions.
`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
  - OP_EQUALS
```
static final String OP_EQUALS
```
    Equality operator. (=)
    
    See Also:
    Constant Field Values
  - OP_NOT_EQUALS
```
static final String OP_NOT_EQUALS
```
    Inequality operator. (<>)
    
    See Also:
    Constant Field Values
  - OP_GREATER
```
static final String OP_GREATER
```
    Greater then operator. (>)
    
    See Also:
    Constant Field Values
  - OP_GREATER_EQUALS
```
static final String OP_GREATER_EQUALS
```
    Greater then or equals operator. (>=)
    
    See Also:
    Constant Field Values
  - OP_LESS
```
static final String OP_LESS
```
    Less then operator. (<)
    
    See Also:
    Constant Field Values
  - OP_LESS_EQUALS
```
static final String OP_LESS_EQUALS
```
    Less then or equals operator. (<=)
    
    See Also:
    Constant Field Values
  - OP_LIKE
```
static final String OP_LIKE
```
    Like operator. (LIKE)
    
    See Also:
    Constant Field Values
  - OP_NOT_LIKE
```
static final String OP_NOT_LIKE
```
    Not like operator. (NOT LIKE)
    
    See Also:
    Constant Field Values
  - OP_BETWEEN
```
static final String OP_BETWEEN
```
    Between operator. (BETWEEN)
    
    See Also:
    Constant Field Values
  - OP_BETWEEN_AND
```
static final String OP_BETWEEN_AND
```
    Between and operator. (AND)
    
    See Also:
    Constant Field Values
- Method Detail
  - addColumn
```
void addColumn(String tableName,
             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(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(String tableName,
            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(String tableName,
                String columnName,
                String condOp)
```
    Add a query paramater.
    
    Parameters:
    tableName - The table name
    columnName - The column name
    condOp - The conditional operation
  - addCondition
```
void addCondition(String tableName,
                String columnName,
                String condOp,
                String value)
```
    Add a condition.
    
    Parameters:
    tableName - The table name
    columnName - The column name
    condOp - The conditional operation
    value - The conditional value
  - encodeColumn
```
String encodeColumn(String tableName,
                  String columnName)
```
    Encode a TableColumn for use in expressions.
    
    Parameters:
    tableName - The table name.
    columnName - The column name.
  - addWhereClause
```
void addWhereClause(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(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(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(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(String leftTable,
                String[] leftColumn,
                String leftTableAlias,
                String rightTable,
                String[] rightColumn,
                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(String leftTable,
                String[] leftColumn,
                String rightTable,
                String[] rightColumn,
                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
  - getStatement
```
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
```
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

Interface QueryExpression

Field Summary

Method Summary

Field Detail

OP_EQUALS

OP_NOT_EQUALS

OP_GREATER

OP_GREATER_EQUALS

OP_LESS

OP_LESS_EQUALS

OP_LIKE

OP_NOT_LIKE

OP_BETWEEN

OP_BETWEEN_AND

Method Detail

addColumn

addSelect

setDistinct

addTable

addParameter

addCondition

encodeColumn

addWhereClause

addOrderClause

addLimitClause

addOffsetClause

addInnerJoin

addOuterJoin

getStatement

clone

isLimitClauseSupported

isOffsetClauseSupported

setDbMetaInfo