javatools.db
Class DbOrExpr

java.lang.Object
  |
  +--javatools.db.DbExpr
        |
        +--javatools.db.DbCriterion
              |
              +--javatools.db.DbOrExpr

public class DbOrExpr

extends DbCriterion

An expression of the form A OR B. The reason we have this class as well as DbCriterion, is that this class will optimise away unnecessary segments. i.e. A OR FALSE will be optimised to just A. The reason you may find a FALSE expression in your code is the use of DbDatabase.falseExpr(). This is a very convenient thing for dynamically generated queries. Of course we could just leave the dummy false expressions in the final SQL and presumably the dbms can optimise it away fine, but it looks a bit ugly and nasty to have these dummy expressions in the result.

See Also:

DbFalseExpr.

Field Summary

Fields inherited from class javatools.db.DbCriterion

c1, c2, op

Fields inherited from class javatools.db.DbExpr

db

Constructor Summary

DbOrExpr(DbDatabase db, java.lang.Object o1, java.lang.Object o2)

Method Summary

java.lang.String	getQueryString() Any DbExpr needs to be able to convert into the SQL string equivilent.
int	setSqlValues(java.sql.PreparedStatement ps, int i) Any DbExpr needs to be able to substitute any parameters as per JDBC "?" substitutions.

Methods inherited from class javatools.db.DbCriterion

usesTables

Methods inherited from class javatools.db.DbExpr

and, dateTrunc, equal, getString, greaterThan, greaterThanOrEqual, in, isNotNull, isNull, lessThan, lessThanOrEqual, like, lower, max, min, notEqual, notIn, or, setSqlValue, upper, usesTables

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DbOrExpr

public DbOrExpr(DbDatabase db,
                java.lang.Object o1,
                java.lang.Object o2)

Method Detail

setSqlValues

public int setSqlValues(java.sql.PreparedStatement ps,
                        int i)
                 throws java.sql.SQLException,
                        DbException

Description copied from class: DbExpr

Any DbExpr needs to be able to substitute any parameters as per JDBC "?" substitutions.

Overrides:

setSqlValues in class DbCriterion

Parameters:

ps - The new sqlValues value

i - The new sqlValues value

Returns:

Description of the Returned Value

Throws:

DbException - Description of Exception

java.sql.SQLException - Description of Exception

getQueryString

public java.lang.String getQueryString()
                                throws DbException

Description copied from class: DbExpr

Any DbExpr needs to be able to convert into the SQL string equivilent.

Overrides:

getQueryString in class DbCriterion

Returns:

The queryString value

Throws:

DbException - Description of Exception