SQLParser (jTDS API)

java.lang.Object
- net.sourceforge.jtds.jdbc.SQLParser

```
class SQLParser
extends java.lang.Object
```
Process JDBC escape strings and parameter markers in the SQL string.
This code recognizes the following escapes:
1. Date {d 'yyyy-mm-dd'}
2. Time {t 'hh:mm:ss'}
3. Timestamp {ts 'yyyy-mm-dd hh:mm:ss.nnn'}
4. ESCAPE {escape 'x'}
5. Function {fn xxxx([arg,arg...])} NB The concat(arg, arg) operator is converted to (arg + arg)
6. OuterJoin {oj .....}
7. Call {?=call proc [arg, arg...]} or {call proc [arg, arg...]}
Notes:
1. This code is designed to be as efficient as possible and as result the validation done here is limited.
2. SQL comments are parsed correctly thanks to code supplied by Joel Fouse.
Version:

$Id: SQLParser.java,v 1.29 2007/07/08 17:28:23 bheineman Exp $

Author:

Mike Hutchinson

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`private static class`	`SQLParser.CachedSQLQuery` Serialized version of a parsed SQL query (the value stored in the cache for a parsed SQL).

Field Summary

Fields
Modifier and Type	Field and Description
`private static SimpleLRUCache`	`cache` LRU cache of previously parsed SQL
`private ConnectionJDBC2`	`connection` Connection object for server specific parsing.
`private static java.util.HashMap`	`cvMap` Map of jdbc to server data types for convert
`private int`	`d` Current position in output buffer.
`private static byte[]`	`dateMask` Syntax mask for date escape.
`private static java.util.HashMap`	`fnMap` Map of jdbc to sybase function names.
`private static boolean[]`	`identifierChar` Lookup table to test if character is part of an identifier.
`private char[]`	`in` Input buffer with SQL statement.
`private java.lang.String`	`keyWord` First SQL keyword or identifier in statement.
`private int`	`len` Length of input buffer.
`private static java.util.HashMap`	`msFnMap` Map of jdbc to sql server function names.
`private char[]`	`out` Output buffer to contain parsed SQL.
`private java.util.ArrayList`	`params` Parameter list to be populated or `null` if no parameters are expected.
`private java.lang.String`	`procName` Procedure name in call escape.
`private int`	`s` Current position in input buffer.
`private java.lang.String`	`sql` Original SQL string
`private java.lang.String`	`tableName` First table name in from clause
`private char`	`terminator` Current expected terminator character.
`private static byte[]`	`timeMask` Syntax mask for time escape.
`(package private) static byte[]`	`timestampMask` Syntax mask for timestamp escape.

Constructor Summary

Constructors
Modifier	Constructor and Description
`private`	`SQLParser(java.lang.String sqlIn, java.util.ArrayList paramList, ConnectionJDBC2 connection)` Constructs a new parser object to process the supplied SQL.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`private void`	`callEscape()` Processes the JDBC {call procedure [(?,?,?)]} type escape.
`private java.lang.String`	`copyKeyWord()` Copies over possible SQL keyword eg 'SELECT'
`private void`	`copyLiteral(java.lang.String txt)` Inserts a String literal in the output buffer.
`private void`	`copyParam(java.lang.String name, int pos)` Builds a new parameter item.
`private java.lang.String`	`copyParamName()` Copies an embedded parameter name to the output buffer.
`private java.lang.String`	`copyProcName()` Copies an embedded stored procedure identifier over to the output buffer.
`private void`	`copyString()` Copies over an embedded string literal unchanged.
`private void`	`copyWhiteSpace()` Copies over white space.
`private void`	`escape()` Processes the JDBC escape sequences.
`private void`	`functionEscape()` Processes the JDBC escape {fn function()}.
`private static SimpleLRUCache`	`getCache(ConnectionJDBC2 connection)` Retrieves the statement cache, creating it if required.
`private boolean`	`getDateTimeField(byte[] mask)` Utility routine to validate date and time escapes.
`private java.lang.String`	`getTableName()` Extracts the first table name following the keyword FROM.
`private static boolean`	`isIdentifier(int ch)` Determines if character could be part of an SQL identifier.
`private void`	`likeEscape()` Processes the JDBC escape {escape 'X'}.
`private void`	`mustbe(char c, boolean copy)` Checks that the next character is as expected.
`private void`	`outerJoinEscape()` Processes the JDBC escape {oj left outer join etc}.
`(package private) java.lang.String[]`	`parse(boolean extractTable)` Parses the SQL statement processing JDBC escapes and parameter markers.
`(package private) static java.lang.String[]`	`parse(java.lang.String sql, java.util.ArrayList paramList, ConnectionJDBC2 connection, boolean extractTable)` Parse the SQL statement processing JDBC escapes and parameter markers.
`private void`	`skipMultiComments()` Skips multi-line comments
`private void`	`skipSingleComments()` Skips single-line comments.
`private void`	`skipWhiteSpace()` Skips embedded white space.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - cache
```
private static SimpleLRUCache cache
```
    LRU cache of previously parsed SQL
  - sql
```
private final java.lang.String sql
```
    Original SQL string
  - in
```
private final char[] in
```
    Input buffer with SQL statement.
  - s
```
private int s
```
    Current position in input buffer.
  - len
```
private final int len
```
    Length of input buffer.
  - out
```
private final char[] out
```
    Output buffer to contain parsed SQL.
  - d
```
private int d
```
    Current position in output buffer.
  - params
```
private final java.util.ArrayList params
```
    Parameter list to be populated or null if no parameters are expected.
  - terminator
```
private char terminator
```
    Current expected terminator character.
  - procName
```
private java.lang.String procName
```
    Procedure name in call escape.
  - keyWord
```
private java.lang.String keyWord
```
    First SQL keyword or identifier in statement.
  - tableName
```
private java.lang.String tableName
```
    First table name in from clause
  - connection
```
private final ConnectionJDBC2 connection
```
    Connection object for server specific parsing.
  - identifierChar
```
private static boolean[] identifierChar
```
    Lookup table to test if character is part of an identifier.
  - timeMask
```
private static final byte[] timeMask
```
    Syntax mask for time escape.
  - dateMask
```
private static final byte[] dateMask
```
    Syntax mask for date escape.
  - timestampMask
```
static final byte[] timestampMask
```
    Syntax mask for timestamp escape.
  - fnMap
```
private static java.util.HashMap fnMap
```
    Map of jdbc to sybase function names.
  - msFnMap
```
private static java.util.HashMap msFnMap
```
    Map of jdbc to sql server function names.
  - cvMap
```
private static java.util.HashMap cvMap
```
    Map of jdbc to server data types for convert
- Constructor Detail
  - SQLParser
```
private SQLParser(java.lang.String sqlIn,
                  java.util.ArrayList paramList,
                  ConnectionJDBC2 connection)
```
    Constructs a new parser object to process the supplied SQL.
    
    Parameters:
    
    sqlIn - the SQL statement to parse
    
    paramList - the parameter list array to populate or null if no parameters are expected
    
    connection - the parent Connection object
- Method Detail
  - parse
```
static java.lang.String[] parse(java.lang.String sql,
                                java.util.ArrayList paramList,
                                ConnectionJDBC2 connection,
                                boolean extractTable)
                         throws java.sql.SQLException
```
    Parse the SQL statement processing JDBC escapes and parameter markers.
    
    Parameters:
    
    extractTable - true to return the first table name in the FROM clause of a select
    
    Returns:
    
    The processed SQL statement, any procedure name, the first SQL keyword and (optionally) the first table name as elements 0 1, 2 and 3 of the returned String[].
    
    Throws:
    
    java.sql.SQLException - if a parse error occurs
  - getCache
```
private static SimpleLRUCache getCache(ConnectionJDBC2 connection)
```
    Retrieves the statement cache, creating it if required.
    
    Returns:
    
    the cache as a SimpleLRUCache
  - isIdentifier
```
private static boolean isIdentifier(int ch)
```
    Determines if character could be part of an SQL identifier.
    Characters > 127 are assumed to be unicode letters in other languages than english which is reasonable in this application.
    
    Parameters:
    
    ch - the character to test.
    
    Returns:
    
    boolean true if ch in A-Z a-z 0-9 @ $ # _.
  - copyLiteral
```
private void copyLiteral(java.lang.String txt)
                  throws java.sql.SQLException
```
    Inserts a String literal in the output buffer.
    
    Parameters:
    
    txt - The text to insert.
    
    Throws:
    
    java.sql.SQLException
  - copyString
```
private void copyString()
```
    Copies over an embedded string literal unchanged.
  - copyKeyWord
```
private java.lang.String copyKeyWord()
```
    Copies over possible SQL keyword eg 'SELECT'
  - copyParam
```
private void copyParam(java.lang.String name,
                       int pos)
                throws java.sql.SQLException
```
    Builds a new parameter item.
    
    Parameters:
    
    name - Optional parameter name or null.
    
    pos - The parameter marker position in the output buffer.
    
    Throws:
    
    java.sql.SQLException
  - copyProcName
```
private java.lang.String copyProcName()
                               throws java.sql.SQLException
```
    Copies an embedded stored procedure identifier over to the output buffer.
    
    Returns:
    
    The identifier as a String.
    
    Throws:
    
    java.sql.SQLException
  - copyParamName
```
private java.lang.String copyParamName()
```
    Copies an embedded parameter name to the output buffer.
    
    Returns:
    
    The identifier as a String.
  - copyWhiteSpace
```
private void copyWhiteSpace()
```
    Copies over white space.
  - mustbe
```
private void mustbe(char c,
                    boolean copy)
             throws java.sql.SQLException
```
    Checks that the next character is as expected.
    
    Parameters:
    
    c - The expected character.
    
    copy - True if found character should be copied.
    
    Throws:
    
    java.sql.SQLException - if expected characeter not found.
  - skipWhiteSpace
```
private void skipWhiteSpace()
```
    Skips embedded white space.
  - skipSingleComments
```
private void skipSingleComments()
```
    Skips single-line comments.
  - skipMultiComments
```
private void skipMultiComments()
                        throws java.sql.SQLException
```
    Skips multi-line comments
    
    Throws:
    
    java.sql.SQLException
  - callEscape
```
private void callEscape()
                 throws java.sql.SQLException
```
    Processes the JDBC {call procedure [(?,?,?)]} type escape.
    
    Throws:
    
    java.sql.SQLException - if an error occurs
  - getDateTimeField
```
private boolean getDateTimeField(byte[] mask)
                          throws java.sql.SQLException
```
    Utility routine to validate date and time escapes.
    
    Parameters:
    
    mask - The validation mask
    
    Returns:
    
    True if the escape was valid and processed OK.
    
    Throws:
    
    java.sql.SQLException
  - outerJoinEscape
```
private void outerJoinEscape()
                      throws java.sql.SQLException
```
    Processes the JDBC escape {oj left outer join etc}.
    
    Throws:
    
    java.sql.SQLException
  - functionEscape
```
private void functionEscape()
                     throws java.sql.SQLException
```
    Processes the JDBC escape {fn function()}.
    
    Throws:
    
    java.sql.SQLException
  - likeEscape
```
private void likeEscape()
                 throws java.sql.SQLException
```
    Processes the JDBC escape {escape 'X'}.
    
    Throws:
    
    java.sql.SQLException
  - escape
```
private void escape()
             throws java.sql.SQLException
```
    Processes the JDBC escape sequences.
    
    Throws:
    
    java.sql.SQLException
  - getTableName
```
private java.lang.String getTableName()
                               throws java.sql.SQLException
```
    Extracts the first table name following the keyword FROM.
    
    Returns:
    
    the table name as a String
    
    Throws:
    
    java.sql.SQLException
  - parse
```
java.lang.String[] parse(boolean extractTable)
                  throws java.sql.SQLException
```
    Parses the SQL statement processing JDBC escapes and parameter markers.
    
    Parameters:
    
    extractTable - true to return the first table name in the FROM clause of a select
    
    Returns:
    
    The processed SQL statement, any procedure name, the first SQL keyword and (optionally) the first table name as elements 0 1, 2 and 3 of the returned String[].
    
    Throws:
    
    java.sql.SQLException

Class SQLParser

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

cache

sql

in

s

len

out

d

params

terminator

procName

keyWord

tableName

connection

identifierChar

timeMask

dateMask

timestampMask

fnMap

msFnMap

cvMap

Constructor Detail

SQLParser

Method Detail

parse

getCache

isIdentifier

copyLiteral

copyString

copyKeyWord

copyParam

copyProcName

copyParamName

copyWhiteSpace

mustbe

skipWhiteSpace

skipSingleComments

skipMultiComments

callEscape

getDateTimeField

outerJoinEscape

functionEscape

likeEscape

escape

getTableName

parse