org.h2.expression
Class CompareLike

java.lang.Object
  extended by org.h2.expression.Expression
      extended by org.h2.expression.Condition
          extended by org.h2.expression.CompareLike

public class CompareLike
extends Condition

Pattern matching comparison expression: WHERE NAME LIKE ?


Constructor Summary
CompareLike(CompareMode compareMode, java.lang.String defaultEscape, Expression left, Expression right, Expression escape, boolean regexp)
           
CompareLike(Database db, Expression left, Expression right, Expression escape, boolean regexp)
           
 
Method Summary
 void createIndexConditions(Session session, TableFilter filter)
          Create index conditions if possible and attach them to the table filter.
 int getCost()
          Estimate the cost to process the expression.
 java.lang.String getSQL()
          Get the SQL statement of this expression.
 Value getValue(Session session)
          Return the resulting value for the current row.
 boolean isEverything(ExpressionVisitor visitor)
          Check if this expression and all sub-expressions can fulfill a criteria.
 void mapColumns(ColumnResolver resolver, int level)
          Map the columns of the resolver to expression columns.
 Expression optimize(Session session)
          Try to optimize the expression.
 void setEvaluatable(TableFilter tableFilter, boolean b)
          Tell the expression columns whether the table filter can return values now.
 boolean test(java.lang.String testPattern, java.lang.String value, char escapeChar)
          Test if the value matches the pattern.
 void updateAggregate(Session session)
          Update an aggregate value.
 
Methods inherited from class org.h2.expression.Condition
getDisplaySize, getPrecision, getScale, getType
 
Methods inherited from class org.h2.expression.Expression
addFilterConditions, getAlias, getBooleanValue, getColumnName, getExpressionColumns, getExpressionColumns, getExpressionColumns, getNonAliasExpression, getNotIfPossible, getNullable, getSchemaName, getTableAlias, getTableName, isAutoIncrement, isConstant, isEverything, isValueSet, isWildcard, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

CompareLike

public CompareLike(Database db,
                   Expression left,
                   Expression right,
                   Expression escape,
                   boolean regexp)

CompareLike

public CompareLike(CompareMode compareMode,
                   java.lang.String defaultEscape,
                   Expression left,
                   Expression right,
                   Expression escape,
                   boolean regexp)
Method Detail

getSQL

public java.lang.String getSQL()
Description copied from class: Expression
Get the SQL statement of this expression. This may not always be the original SQL statement, specially after optimization.

Specified by:
getSQL in class Expression
Returns:
the SQL statement

optimize

public Expression optimize(Session session)
Description copied from class: Expression
Try to optimize the expression.

Specified by:
optimize in class Expression
Parameters:
session - the session
Returns:
the optimized expression

createIndexConditions

public void createIndexConditions(Session session,
                                  TableFilter filter)
Description copied from class: Expression
Create index conditions if possible and attach them to the table filter.

Overrides:
createIndexConditions in class Expression
Parameters:
session - the session
filter - the table filter

getValue

public Value getValue(Session session)
Description copied from class: Expression
Return the resulting value for the current row.

Specified by:
getValue in class Expression
Parameters:
session - the session
Returns:
the result

test

public boolean test(java.lang.String testPattern,
                    java.lang.String value,
                    char escapeChar)
Test if the value matches the pattern.

Parameters:
testPattern - the pattern
value - the value
escapeChar - the escape character
Returns:
true if the value matches

mapColumns

public void mapColumns(ColumnResolver resolver,
                       int level)
Description copied from class: Expression
Map the columns of the resolver to expression columns.

Specified by:
mapColumns in class Expression
Parameters:
resolver - the column resolver
level - the subquery nesting level

setEvaluatable

public void setEvaluatable(TableFilter tableFilter,
                           boolean b)
Description copied from class: Expression
Tell the expression columns whether the table filter can return values now. This is used when optimizing the query.

Specified by:
setEvaluatable in class Expression
Parameters:
tableFilter - the table filter
b - true if the table filter can return value

updateAggregate

public void updateAggregate(Session session)
Description copied from class: Expression
Update an aggregate value. This method is called at statement execution time. It is usually called once for each row, but if the expression is used multiple times (for example in the column list, and as part of the HAVING expression) it is called multiple times - the row counter needs to be used to make sure the internal state is only updated once.

Specified by:
updateAggregate in class Expression
Parameters:
session - the session

isEverything

public boolean isEverything(ExpressionVisitor visitor)
Description copied from class: Expression
Check if this expression and all sub-expressions can fulfill a criteria. If any part returns false, the result is false.

Specified by:
isEverything in class Expression
Parameters:
visitor - the visitor
Returns:
if the criteria can be fulfilled

getCost

public int getCost()
Description copied from class: Expression
Estimate the cost to process the expression. Used when optimizing the query, to calculate the query plan with the lowest estimated cost.

Specified by:
getCost in class Expression
Returns:
the estimated cost