Module litebridge.db.spi.impl

Package org.litebridgedb.db.spi.impl.function.scalar

Class Substring

java.lang.Object

org.litebridgedb.db.spi.expression.ColumnExpressionImpl

org.litebridgedb.db.spi.expression.DelegateColumnExpression

org.litebridgedb.db.spi.impl.function.AliasedDelegateColumnExpression

org.litebridgedb.db.spi.impl.function.FunctionExpression

org.litebridgedb.db.spi.impl.function.scalar.Substring

All Implemented Interfaces:

ColumnExpression, DelegateExpression, SelectExpression

public class Substring
extends FunctionExpression

SUBSTRING(column, start, length) scalar function.

Field Summary

Fields

Modifier and Type	Field	Description
protected final @Nullable Integer	length
protected final int	start	Database index, 1-based.

Fields inherited from class org.litebridgedb.db.spi.impl.function.AliasedDelegateColumnExpression

columnIdentifierGenerator

Fields inherited from class org.litebridgedb.db.spi.expression.DelegateColumnExpression

target

Fields inherited from class org.litebridgedb.db.spi.expression.ColumnExpressionImpl

column

Constructor Summary

Constructors

Constructor	Description
Substring(ColumnExpression target, int start, @Nullable Integer length, ColumnIdentifierGenerator columnIdentifierGenerator)	Construct a SUBSTRING function.

Method Summary

Modifier and Type	Method	Description
protected String	template()	Gets the template for the SQL representation of the function.

Methods inherited from class org.litebridgedb.db.spi.impl.function.FunctionExpression

prepareSql, toSql, toSqlWithAlias

Methods inherited from class org.litebridgedb.db.spi.impl.function.AliasedDelegateColumnExpression

id, idWithAlias, localId

Methods inherited from class org.litebridgedb.db.spi.expression.DelegateColumnExpression

column, target

Methods inherited from class java.lang.Object

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

Field Details

start

protected final int start

Database index, 1-based.

length

protected final @Nullable Integer length

Constructor Details

Substring

public Substring(ColumnExpression target,
 int start,
 @Nullable Integer length,
 ColumnIdentifierGenerator columnIdentifierGenerator)

Construct a SUBSTRING function.

Parameters:

target - Target expression to extract characters from.

start - The starting position. The first character of a database string is always 1.

length - The number of characters to return. If null, the function extracts everything from the start position to the end of the text.

columnIdentifierGenerator - Database provider-specific column identifier generator.

Method Details

template

protected String template()

Description copied from class: FunctionExpression

Gets the template for the SQL representation of the function.

The template should contain a single "%s" placeholder for the column identifier.

Specified by:

template in class FunctionExpression

Returns:

SQL representation template