Package net.sourceforge.jtds.jdbc
Class SQLParser
- java.lang.Object
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- net.sourceforge.jtds.jdbc.SQLParser
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class SQLParser extends java.lang.Object
Process JDBC escape strings and parameter markers in the SQL string.This code recognizes the following escapes:
- Date {d 'yyyy-mm-dd'}
- Time {t 'hh:mm:ss'}
- Timestamp {ts 'yyyy-mm-dd hh:mm:ss.nnn'}
- ESCAPE {escape 'x'}
- Function {fn xxxx([arg,arg...])} NB The concat(arg, arg) operator is converted to (arg + arg)
- OuterJoin {oj .....}
- Call {?=call proc [arg, arg...]} or {call proc [arg, arg...]}
- This code is designed to be as efficient as possible and as result the validation done here is limited.
- Author:
- Mike Hutchinson, Holger Rehn
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Nested Class Summary
Nested Classes Modifier and Type Class Description private static class
SQLParser.CachedSQLQuery
Serialized version of a parsed SQL query (the value stored in the cache for a parsed SQL).
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Field Summary
Fields Modifier and Type Field Description private static SimpleLRUCache<SQLCacheKey,SQLParser.CachedSQLQuery>
_Cache
a LRU cache for the last 500 parsed SQL statementsprivate JtdsConnection
connection
Connection object for server specific parsing.private static java.util.HashMap
cvMap
Map of jdbc to server data types for convertprivate 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 ornull
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 stringprivate java.lang.String
tableName
First table name in from clauseprivate 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.
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Constructor Summary
Constructors Modifier Constructor Description private
SQLParser(java.lang.String sqlIn, java.util.ArrayList paramList, JtdsConnection connection)
Constructs a new parser object to process the supplied SQL.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description private void
append(char character)
private void
append(char[] chars)
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 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, JtdsConnection connection, boolean extractTable)
Parse the SQL statement processing JDBC escapes and parameter markers.private void
skipMultiComments()
Skips multi-line commentsprivate void
skipSingleComments()
Skips single-line comments.private void
skipWhiteSpace()
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Field Detail
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_Cache
private static final SimpleLRUCache<SQLCacheKey,SQLParser.CachedSQLQuery> _Cache
a LRU cache for the last 500 parsed SQL statements
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sql
private final java.lang.String sql
Original SQL string
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in
private final char[] in
Input buffer with SQL statement.
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s
private int s
Current position in input buffer.
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len
private final int len
Length of input buffer.
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out
private char[] out
Output buffer to contain parsed SQL.
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d
private int d
Current position in output buffer.
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params
private final java.util.ArrayList params
Parameter list to be populated ornull
if no parameters are expected.
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terminator
private char terminator
Current expected terminator character.
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procName
private java.lang.String procName
Procedure name in call escape.
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keyWord
private java.lang.String keyWord
First SQL keyword or identifier in statement.
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tableName
private java.lang.String tableName
First table name in from clause
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connection
private final JtdsConnection connection
Connection object for server specific parsing.
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identifierChar
private static boolean[] identifierChar
Lookup table to test if character is part of an identifier.
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timeMask
private static final byte[] timeMask
Syntax mask for time escape.
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dateMask
private static final byte[] dateMask
Syntax mask for date escape.
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timestampMask
static final byte[] timestampMask
Syntax mask for timestamp escape.
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fnMap
private static java.util.HashMap fnMap
Map of jdbc to sybase function names.
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msFnMap
private static java.util.HashMap msFnMap
Map of jdbc to sql server function names.
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cvMap
private static java.util.HashMap cvMap
Map of jdbc to server data types for convert
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Constructor Detail
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SQLParser
private SQLParser(java.lang.String sqlIn, java.util.ArrayList paramList, JtdsConnection connection)
Constructs a new parser object to process the supplied SQL.- Parameters:
sqlIn
- the SQL statement to parseparamList
- the parameter list array to populate ornull
if no parameters are expectedconnection
- the parent Connection object
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Method Detail
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parse
static java.lang.String[] parse(java.lang.String sql, java.util.ArrayList paramList, JtdsConnection 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
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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 @ $ # _.
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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
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copyString
private void copyString()
Copies over an embedded string literal unchanged.
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copyKeyWord
private java.lang.String copyKeyWord()
Copies over possible SQL keyword eg 'SELECT'
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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
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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
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copyParamName
private java.lang.String copyParamName()
Copies an embedded parameter name to the output buffer.- Returns:
- The identifier as a
String
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copyWhiteSpace
private void copyWhiteSpace()
Copies over white space.
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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.
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skipWhiteSpace
private void skipWhiteSpace() throws java.sql.SQLException
- Throws:
java.sql.SQLException
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skipSingleComments
private void skipSingleComments()
Skips single-line comments.
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skipMultiComments
private void skipMultiComments() throws java.sql.SQLException
Skips multi-line comments- Throws:
java.sql.SQLException
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callEscape
private void callEscape() throws java.sql.SQLException
Processes the JDBC {call procedure [(?,?,?)]} type escape.- Throws:
java.sql.SQLException
- if an error occurs
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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
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outerJoinEscape
private void outerJoinEscape() throws java.sql.SQLException
Processes the JDBC escape {oj left outer join etc}.- Throws:
java.sql.SQLException
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functionEscape
private void functionEscape() throws java.sql.SQLException
Processes the JDBC escape {fn function()}.- Throws:
java.sql.SQLException
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likeEscape
private void likeEscape() throws java.sql.SQLException
Processes the JDBC escape {escape 'X'}.- Throws:
java.sql.SQLException
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escape
private void escape() throws java.sql.SQLException
Processes the JDBC escape sequences.- Throws:
java.sql.SQLException
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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
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append
private final void append(char[] chars)
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append
private final void append(char character)
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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
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