javatools.db
Class DbOrExpr

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

All Implemented Interfaces:

DbTableUser

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.

Constructor Summary

DbOrExpr(DbDatabase db, java.lang.Object o1, java.lang.Object o2)
Creates a new OR expression.

Method Summary

java.lang.String	getQueryString() Returns the query string related to this expression.
int	setSqlValues(java.sql.PreparedStatement ps, int i) Puts data into a statement.

Methods inherited from class javatools.db.DbCriterion

usesTables

Methods inherited from class javatools.db.DbExpr

and, containsAllStrings, containsAllStrings, count, dateTrunc, equal, greaterThan, greaterThanOrEqual, in, in, isNotNull, isNull, lessThan, lessThanOrEqual, like, lower, max, min, notEqual, notIn, notIn, or, 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)

Creates a new OR expression.

Parameters:

db - The database that will be used.

o1 - The first term.

o2 - The second term.

Method Detail

setSqlValues

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

Puts data into a statement.

Overrides:

setSqlValues in class DbCriterion

Parameters:

ps - The statement.

i - An index (obscure).

Returns:

An index (obscure).

Throws:

java.sql.SQLException - If something goes wrong.

DbException - If something goes wrong.

getQueryString

public java.lang.String getQueryString()
                                throws DbException

Returns the query string related to this expression.

Overrides:

getQueryString in class DbCriterion

Returns:

The requested query string.

Throws:

DbException - If something goes wrong.