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.
|
void |
setType(DBJoinType type)
alters the join type for this join
|
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 void setType(DBJoinType type)
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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