Package org.apache.empire.db.expr.join

Class DBColumnJoinExpr

java.lang.Object
org.apache.empire.db.DBObject
org.apache.empire.db.DBExpr
org.apache.empire.db.expr.join.DBJoinExpr
org.apache.empire.db.expr.join.DBColumnJoinExpr
All Implemented Interfaces:
DBPreparable
Direct Known Subclasses:
DBCompareJoinExpr
public class DBColumnJoinExpr extends DBJoinExpr

  • Field Details

  • Constructor Details

    • DBColumnJoinExpr

      public DBColumnJoinExpr(DBColumnExpr left, DBColumnExpr right, DBJoinType type, DBCompareExpr addlConstraint)
      Constructs a join expression based on two columns or column expressions
      Parameters:
      left - left value
      right - right value
      type - data type (JOIN_INNER, JOIN_LEFT or JOIN_RIGHT)
      addlConstraint - additional constraint

    • DBColumnJoinExpr

      public DBColumnJoinExpr(DBColumnExpr left, DBColumnExpr right, DBJoinType type)

    • DBColumnJoinExpr

      public DBColumnJoinExpr(DBColumnJoinExpr joinExpr, DBCompareExpr addlConstraint)
      Copy and concat constructor
      Parameters:
      joinExpr - the original joinExpr
      addlConstraint - additional constraint

  • Method Details

    • getDatabase

      public final DBDatabase getDatabase()
      Returns the current DBDatabase object.
      Specified by:
      getDatabase in class DBObject
      Returns:
      the current DBDatabase object

    • getLeft

      public DBColumnExpr getLeft()
      returns the left join expression
      Returns:
      the left column expression

    • getRight

      public DBColumnExpr getRight()
      returns the right join expression
      Returns:
      the right column expression

    • getLeftTable

      public DBRowSet getLeftTable()
      Description copied from class: DBJoinExpr
      returns the RowSet on the left of the join
      Specified by:
      getLeftTable in class DBJoinExpr
      Returns:
      the rowset on the left

    • getRightTable

      public DBRowSet getRightTable()
      returns the RowSet on the right of the join
      Specified by:
      getRightTable in class DBJoinExpr
      Returns:
      the rowset on the right

    • isJoinOn

      public boolean isJoinOn(DBRowSet rowset)
      returns true if this join is using the given table or view or false otherwise
      Specified by:
      isJoinOn in class DBJoinExpr
      Parameters:
      rowset - the rowset to check
      Returns:
      true if the join is on the given rowset

    • isJoinOn

      public boolean isJoinOn(DBColumn column)
      returns true if this join is using the given column or false otherwise
      Specified by:
      isJoinOn in class DBJoinExpr
      Parameters:
      column - the column to check
      Returns:
      true if the join is on the given column

    • getOuterTable

      public DBRowSet getOuterTable()
      Returns the left table name if the data type= JOIN_LEFT and returns the right table if the data type= JOIN_RIGHT. If the data type = JOIN_INNER the return value is null.
      Specified by:
      getOuterTable in class DBJoinExpr
      Returns:
      the current DBDatabase object

    • reverse

      public void reverse()
      This function swaps the left and the right statements of the join expression.
      Specified by:
      reverse in class DBJoinExpr

    • prepareParams

      public void prepareParams(DBCommand cmd, DBExpr parent)
      Description copied from interface: DBPreparable
      Prepares an expression for a query This function is called by DBCommand in order to add values as query parameters instead of being literally included in the sql statement Please Note: This function is internally called. Do not call yourself!
      Parameters:
      cmd - the command to which to add the parameters
      parent - the parent expression holding the value

    • copy

      public DBJoinExpr copy(DBCommand newCmd)
      Copy Command
      Specified by:
      copy in class DBJoinExpr
      Parameters:
      newCmd - the new command object
      Returns:
      the join expression

    • getWhere

      public DBCompareExpr getWhere()
      Returns any additional constraints to the join
      Returns:
      a compare expression containing additional constraints or null

    • where

      public void where(DBCompareExpr expr)
      This function adds an additional constraint to the join.
      Parameters:
      expr - the compare expression

    • and

      public DBColumnJoinExpr and(DBCompareExpr expr)
      This function adds an additional constraint to the join.
      Parameters:
      expr - the expression to add
      Returns:
      the object itself

    • and

      public DBColumnJoinExpr and(DBColumnExpr c1, DBColumnExpr c2)
      This function adds an additional constraint to the join.
      Parameters:
      c1 - the first column
      c2 - the second column
      Returns:
      the object itself

    • addReferencedColumns

      public void addReferencedColumns(Set<DBColumn> list)
      Description copied from class: DBExpr
      Internal function to obtain all DBColumnExpr-objects used by this expression.
      Specified by:
      addReferencedColumns in class DBExpr
      Parameters:
      list - list to which all used column expressions must be added
      See Also:

    • addSQL

      public void addSQL(DBSQLBuilder sql, long context)
      Not allowed, this operation have to be done in the DBCommand object.
      Specified by:
      addSQL in class DBExpr
      Parameters:
      sql - the string buffer used to build the sql command
      context - context flag for this SQL-Command (see CTX_??? constants).

    • toString

      public String toString()
      For Debugging
      Overrides:
      toString in class Object

    • equals

      public boolean equals(Object obj)
      Compares two DBJoinExpr objects.
      Overrides:
      equals in class Object
      Parameters:
      obj - other DBJoinExpr object
      Returns:
      true if the other DBJoinExpr object is equal to this object