public abstract class DBJoinExpr extends DBExpr
There is no need to explicitly create instances of this class.
Instead use @link org.apache.empire.db.DBCommand#join(DBColumnExpr, DBColumn, DBJoinType)
Modifier and Type | Field and Description |
---|---|
protected DBJoinType |
type |
CTX_ALIAS, CTX_ALL, CTX_DEFAULT, CTX_FULLNAME, CTX_NAME, CTX_NOPARENTHESES, CTX_VALUE
Modifier | Constructor and Description |
---|---|
protected |
DBJoinExpr(DBJoinType type)
Constructs a new DBJoinExpr object initialize this object with
the left and right column and the data type of the join
expression.
|
Modifier and Type | Method and Description |
---|---|
abstract DBRowSet |
getLeftTable()
returns the RowSet on the left of the join
|
abstract DBRowSet |
getOuterTable()
Returns the left table name if the data type= JOIN_LEFT and returns
the right table if the data type= JOIN_RIGHT.
|
abstract DBRowSet |
getRightTable()
returns the RowSet on the right of the join
|
DBJoinType |
getType()
returns the join type for this join
|
abstract boolean |
isJoinOn(DBColumn column)
returns true if this join is using the given column or false otherwise
|
abstract boolean |
isJoinOn(DBRowSet rowset)
returns true if this join is using the given table or view or false otherwise
|
abstract void |
reverse()
This function swaps the left and the right statements of the join expression.
|
addReferencedColumns, addSQL, getObjectValue, getValueClass
getDatabase
protected DBJoinType type
protected DBJoinExpr(DBJoinType type)
left
- left valueright
- right valuetype
- data type (JOIN_INNER, JOIN_LEFT or JOIN_RIGHT)public DBJoinType getType()
public abstract DBRowSet getLeftTable()
public abstract DBRowSet getRightTable()
public abstract boolean isJoinOn(DBRowSet rowset)
public abstract boolean isJoinOn(DBColumn column)
public abstract DBRowSet getOuterTable()
public abstract void reverse()
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