org.datanucleus.store.rdbms.sql.expression

Class StringExpression

java.lang.Object

org.datanucleus.store.rdbms.sql.expression.SQLExpression

org.datanucleus.store.rdbms.sql.expression.StringExpression

Direct Known Subclasses:

StringLiteral, StringSubqueryExpression

public class StringExpression
extends SQLExpression

Representation of an expression with a string.

Nested Class Summary

Nested classes/interfaces inherited from class org.datanucleus.store.rdbms.sql.expression.SQLExpression

SQLExpression.ColumnExpressionList

Field Summary

Fields inherited from class org.datanucleus.store.rdbms.sql.expression.SQLExpression

lowestOperator, mapping, parameterName, st, stmt, subExprs, table

Constructor Summary

Constructors

Constructor and Description
StringExpression(org.datanucleus.query.expression.Expression.MonadicOperator op, SQLExpression expr1) Perform an operation
StringExpression(SQLExpression expr1, org.datanucleus.query.expression.Expression.DyadicOperator op, SQLExpression expr2) Perform an operation
StringExpression(SQLStatement stmt, JavaTypeMapping mapping, String functionName, List args) Generates statement as e.g.
StringExpression(SQLStatement stmt, JavaTypeMapping mapping, String functionName, List args, List types) Generates statement as e.g.
StringExpression(SQLStatement stmt, SQLTable table, JavaTypeMapping mapping) Constructor for an SQL expression for a (field) mapping in a specified table.

Method Summary

Modifier and Type	Method and Description
SQLExpression	add(SQLExpression expr) Additive Operator.
BooleanExpression	eq(SQLExpression expr) Equality operator (equals to)
BooleanExpression	ge(SQLExpression expr) Relational operator (greater than or equals)
BooleanExpression	gt(SQLExpression expr) Relational operator (greater than)
BooleanExpression	in(SQLExpression expr, boolean not) In expression.
SQLExpression	invoke(String methodName, List args) Invocation of a method on this expression.
BooleanExpression	le(SQLExpression expr) Relational operator (lower than or equals)
BooleanExpression	lt(SQLExpression expr) Relational operator (lower than)
BooleanExpression	ne(SQLExpression expr) Not equality operator (not equals to)

Methods inherited from class org.datanucleus.store.rdbms.sql.expression.SQLExpression

and, cast, com, distinct, div, encloseInParentheses, eor, getJavaTypeMapping, getLowestOperator, getNumberOfSubExpressions, getParameterName, getSQLStatement, getSQLTable, getSubExpression, ior, is, isParameter, mod, mul, neg, not, setJavaTypeMapping, sub, toSQLText

Methods inherited from class java.lang.Object

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

Constructor Detail

StringExpression

public StringExpression(SQLStatement stmt,
                        SQLTable table,
                        JavaTypeMapping mapping)

Constructor for an SQL expression for a (field) mapping in a specified table.

Parameters:

stmt - The statement

table - The table in the statement

mapping - The mapping for the field

StringExpression

public StringExpression(org.datanucleus.query.expression.Expression.MonadicOperator op,
                        SQLExpression expr1)

Perform an operation

op

on expression

expr1

.

Parameters:

op - operator

expr1 - operand

StringExpression

public StringExpression(SQLExpression expr1,
                        org.datanucleus.query.expression.Expression.DyadicOperator op,
                        SQLExpression expr2)

Perform an operation

op

between

expr1

and

expr2

.

Parameters:

expr1 - the first expression

op - the operator between operands

expr2 - the second expression

StringExpression

public StringExpression(SQLStatement stmt,
                        JavaTypeMapping mapping,
                        String functionName,
                        List args)

Generates statement as e.g. FUNCTION_NAME(arg[,argN]).

Parameters:

stmt - SQL Statement

mapping - Mapping to use

functionName - Name of the function

args - ScalarExpression list

StringExpression

public StringExpression(SQLStatement stmt,
                        JavaTypeMapping mapping,
                        String functionName,
                        List args,
                        List types)

Generates statement as e.g. FUNCTION_NAME(arg AS type[,argN as typeN]).

Parameters:

stmt - SQL Statement

mapping - Mapping to use

functionName - Name of function

args - ScalarExpression list

types - String or ScalarExpression list

Method Detail

eq

public BooleanExpression eq(SQLExpression expr)

Description copied from class: SQLExpression

Equality operator (equals to)

Overrides:

eq in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

The type of an equality expression is a boolean

ne

public BooleanExpression ne(SQLExpression expr)

Description copied from class: SQLExpression

Not equality operator (not equals to)

Overrides:

ne in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

The type of an equality expression is a boolean

lt

public BooleanExpression lt(SQLExpression expr)

Description copied from class: SQLExpression

Relational operator (lower than)

Overrides:

lt in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

true if the value of the left-hand operand is less than the value of the right-hand operand, and otherwise is false.

le

public BooleanExpression le(SQLExpression expr)

Description copied from class: SQLExpression

Relational operator (lower than or equals)

Overrides:

le in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

true if the value of the left-hand operand is less than or equal to the value of the right-hand operand, and otherwise is false.

gt

public BooleanExpression gt(SQLExpression expr)

Description copied from class: SQLExpression

Relational operator (greater than)

Overrides:

gt in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

true if the value of the left-hand operand is greater than the value of the right-hand operand, and otherwise is false.

ge

public BooleanExpression ge(SQLExpression expr)

Description copied from class: SQLExpression

Relational operator (greater than or equals)

Overrides:

ge in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

true if the value of the left-hand operand is greater than or equal the value of the right-hand operand, and otherwise is false.

add

public SQLExpression add(SQLExpression expr)

Description copied from class: SQLExpression

Additive Operator. The binary + operator performs addition when applied to two operands of numeric type, producing the sum of the operands. If the type of either operand of a + operator is String, then the operation is string concatenation.

Overrides:

add in class SQLExpression

Parameters:

expr - the right-hand operand

Returns:

If one of the operands is String, the returned value is the string concatenation; The sum of two operands of numeric type. The left-hand operand is the minuend and the right-hand operand is the subtrahend;

in

public BooleanExpression in(SQLExpression expr,
                            boolean not)

Description copied from class: SQLExpression

In expression. Return true if this is contained by expr

Overrides:

in in class SQLExpression

Parameters:

expr - the right-hand expression

not - Whether we really want "not in"

Returns:

true if the left-hand expression is contained by the right-hand expression. Otherwise the result is false.

invoke

public SQLExpression invoke(String methodName,
                            List args)

Description copied from class: SQLExpression

Invocation of a method on this expression.

Overrides:

invoke in class SQLExpression

Parameters:

methodName - name of the method to invoke

args - Args to this method (if any)

Returns:

the converted value