org.apache.calcite.sql.util

Class SqlBuilder

java.lang.Object

org.apache.calcite.sql.util.SqlBuilder

public class SqlBuilder
extends Object

Extension to StringBuilder for the purposes of creating SQL queries and expressions.

Using this class helps to prevent SQL injection attacks, incorrectly quoted identifiers and strings. These problems occur when you build SQL by concatenating strings, and you forget to treat identifers and string literals correctly. SqlBuilder has special methods for appending identifiers and literals.

Constructor Summary

Constructors

Constructor and Description
SqlBuilder(SqlDialect dialect) Creates a SqlBuilder.
SqlBuilder(SqlDialect dialect, String s) Creates a SqlBuilder with a given string.

Method Summary

Methods

Modifier and Type	Method and Description
SqlBuilder	append(char c) Appends a character, without any quoting.
SqlBuilder	append(long n) Appends a number, per StringBuilder.append(long).
SqlBuilder	append(SqlString s) Appends a hygienic SQL string.
SqlBuilder	append(String s) Appends a string, without any quoting.
void	clear() Clears the contents of the buffer.
SqlDialect	getDialect() Returns the dialect.
String	getSql() Returns the SQL.
String	getSqlAndClear() Returns the SQL and clears the buffer.
SqlBuilder	identifier(List<String> names) Appends a compound identifier to this buffer, quoting accordingly.
SqlBuilder	identifier(String... names) Appends one or more identifiers to this buffer, quoting accordingly.
SqlBuilder	identifier(String name) Appends an identifier to this buffer, quoting accordingly.
int	indexOf(String str) Returns the index within this string of the first occurrence of the specified substring.
int	indexOf(String str, int fromIndex) Returns the index within this string of the first occurrence of the specified substring, starting at the specified index.
SqlBuilder	insert(int offset, String str) Inserts the string into this character sequence.
int	length() Returns the length (character count).
SqlBuilder	literal(String s) Appends a string literal to this buffer.
SqlBuilder	literal(Timestamp timestamp) Appends a timestamp literal to this buffer.
SqlString	toSqlString() Returns the contents of this SQL buffer as a 'certified kocher' SQL string.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

SqlBuilder

public SqlBuilder(SqlDialect dialect)

Creates a SqlBuilder.

Parameters:

dialect - Dialect

SqlBuilder

public SqlBuilder(SqlDialect dialect,
          String s)

Creates a SqlBuilder with a given string.

Parameters:

dialect - Dialect

s - Initial contents of the buffer

Method Detail

getDialect

public SqlDialect getDialect()

Returns the dialect.

Returns:

dialect

length

public int length()

Returns the length (character count).

Returns:

the length of the sequence of characters currently represented by this object

clear

public void clear()

Clears the contents of the buffer.

toString

public String toString()

Returns the SQL string.

Overrides:

toString in class Object

Returns:

SQL string

See Also:

getSql()

getSql

public String getSql()

Returns the SQL.

getSqlAndClear

public String getSqlAndClear()

Returns the SQL and clears the buffer.

Convenient if you are reusing the same SQL builder in a loop.

append

public SqlBuilder append(SqlString s)

Appends a hygienic SQL string.

Parameters:

s - SQL string to append

Returns:

This builder

append

public SqlBuilder append(String s)

Appends a string, without any quoting.

Calls to this method are dubious.

Parameters:

s - String to append

Returns:

This builder

append

public SqlBuilder append(char c)

Appends a character, without any quoting.

Parameters:

c - Character to append

Returns:

This builder

append

public SqlBuilder append(long n)

Appends a number, per StringBuilder.append(long).

identifier

public SqlBuilder identifier(String name)

Appends an identifier to this buffer, quoting accordingly.

Parameters:

name - Identifier

Returns:

This builder

identifier

public SqlBuilder identifier(String... names)

Appends one or more identifiers to this buffer, quoting accordingly.

Parameters:

names - Varargs array of identifiers

Returns:

This builder

identifier

public SqlBuilder identifier(List<String> names)

Appends a compound identifier to this buffer, quoting accordingly.

Parameters:

names - Parts of a compound identifier

Returns:

This builder

toSqlString

public SqlString toSqlString()

Returns the contents of this SQL buffer as a 'certified kocher' SQL string.

Use this method in preference to toString(). It indicates that the SQL string has been constructed using good hygiene, and is therefore less likely to contain SQL injection or badly quoted identifiers or strings.

Returns:

Contents of this builder as a SQL string.

literal

public SqlBuilder literal(String s)

Appends a string literal to this buffer.

For example, calling literal("can't") would convert the buffer

SELECT

to

SELECT 'can''t'

Parameters:

s - String to append

Returns:

This buffer

literal

public SqlBuilder literal(Timestamp timestamp)

Appends a timestamp literal to this buffer.

Parameters:

timestamp - Timestamp to append

Returns:

This buffer

indexOf

public int indexOf(String str)

Returns the index within this string of the first occurrence of the specified substring.

See Also:

StringBuilder.indexOf(String)

indexOf

public int indexOf(String str,
          int fromIndex)

Returns the index within this string of the first occurrence of the specified substring, starting at the specified index.

See Also:

StringBuilder.indexOf(String, int)

insert

public SqlBuilder insert(int offset,
                String str)

Inserts the string into this character sequence.

See Also:

StringBuilder.insert(int, String)