+++ /dev/null
-/*
- * tdbcTokenize.c --
- *
- * Code for a Tcl command that will extract subsitutable parameters
- * from a SQL statement.
- *
- * Copyright (c) 2007 by D. Richard Hipp.
- * Copyright (c) 2010, 2011 by Kevin B. Kenny.
- *
- * Please refer to the file, 'license.terms' for the conditions on
- * redistribution of this file and for a DISCLAIMER OF ALL WARRANTIES.
- *
- * RCS: @(#) $Id$
- *
- *-----------------------------------------------------------------------------
- */
-
-#include "tdbcInt.h"
-#include <ctype.h>
-\f
-/*
- *-----------------------------------------------------------------------------
- *
- * Tdbc_TokenizeSql --
- *
- * Tokenizes a SQL statement.
- *
- * Results:
- * Returns a zero-reference Tcl object that gives the statement in
- * tokenized form, or NULL if an error occurs.
- *
- * Side effects:
- * If an error occurs, and 'interp' is not NULL, stores an error
- * message in the interpreter result.
- *
- * This is demonstration code for a TCL command that will extract
- * host parameters from an SQL statement.
- *
- * A "host parameter" is a variable within the SQL statement.
- * Different systems do host parameters in different ways. This
- * tokenizer recognizes three forms:
- *
- * $ident
- * :ident
- * @ident
- *
- * In other words, a host parameter is an identifier proceeded
- * by one of the '$', ':', or '@' characters.
- *
- * This function returns a Tcl_Obj representing a list. The
- * concatenation of the returned list will be equivalent to the
- * input string. Each element of the list will be either a
- * host parameter, a semicolon, or other text from the SQL
- * statement.
- *
- * Example:
- *
- * tokenize_sql {SELECT * FROM table1 WHERE :name='bob';}
- *
- * Resulting in:
- *
- * {SELECT * FROM table1 WHERE } {:name} {=} {'bob'} {;}
- *
- * The tokenizer knows about SQL comments and strings and will
- * not mistake a host parameter or semicolon embedded in a string
- * or comment as a real host parameter or semicolon.
- *
- *-----------------------------------------------------------------------------
- */
-
-TDBCAPI Tcl_Obj*
-Tdbc_TokenizeSql(
- Tcl_Interp *interp,
- const char* zSql
-){
- Tcl_Obj *resultPtr;
- int i;
-
- resultPtr = Tcl_NewObj();
- for(i = 0; zSql[i]; i++){
- switch( zSql[i] ){
-
- /* Skip over quoted strings. Strings can be quoted in several
- ** ways: '...' "..." [....]
- */
- case '\'':
- case '"':
- case '[': {
- int endChar = zSql[i];
- if (endChar == '[') endChar = ']';
- for(i++; zSql[i] && zSql[i]!=endChar; i++){}
- if (zSql[i] == 0) i--;
- break;
- }
-
- /* Skip over SQL-style comments: -- to end of line
- */
- case '-': {
- if (zSql[i+1] == '-') {
- for(i+=2; zSql[i] && zSql[i]!='\n'; i++){}
- if (zSql[i] == 0) i--;
- }
- break;
- }
-
- /* Skip over C-style comments
- */
- case '/': {
- if (zSql[i+1] == '*') {
- i += 3;
- while (zSql[i] && (zSql[i]!='/' || zSql[i-1]!='*')) {
- i++;
- }
- if (zSql[i] == 0) i--;
- }
- break;
- }
-
- /* Break up multiple SQL statements at each semicolon */
- case ';': {
- if (i>0 ){
- Tcl_ListObjAppendElement(interp, resultPtr,
- Tcl_NewStringObj(zSql, i));
- }
- Tcl_ListObjAppendElement(interp, resultPtr,
- Tcl_NewStringObj(";",1));
- zSql += i + 1;
- i = -1;
- break;
- }
-
- /* Any of the characters ':', '$', or '@' which is followed
- ** by an alphanumeric or '_' and is not preceded by the same
- ** is a host parameter. A name following a doubled colon '::'
- ** is also not a host parameter.
- */
- case ':': {
- if (i > 0 && zSql[i-1] == ':') break;
- }
- /* fallthru */
-
- case '$':
- case '@': {
- if (i>0 && (isalnum((unsigned char)(zSql[i-1]))
- || zSql[i-1]=='_')) break;
- if (!isalnum((unsigned char)(zSql[i+1]))
- && zSql[i+1]!='_') break;
- if (i>0 ){
- Tcl_ListObjAppendElement(interp, resultPtr,
- Tcl_NewStringObj(zSql, i));
- zSql += i;
- }
- i = 1;
- while (zSql[i] && (isalnum((unsigned char)(zSql[i]))
- || zSql[i]=='_')) {
- i++;
- }
- Tcl_ListObjAppendElement(interp, resultPtr,
- Tcl_NewStringObj(zSql, i));
- zSql += i;
- i = -1;
- break;
- }
- }
- }
- if (i>0) {
- Tcl_ListObjAppendElement(interp, resultPtr, Tcl_NewStringObj(zSql, i));
- }
- return resultPtr;
-}
-\f
-/*
- *-----------------------------------------------------------------------------
- *
- * TdbcTokenizeObjCmd --
- *
- * Tcl command to tokenize a SQL statement.
- *
- * Usage:
- * ::tdbc::tokenize statement
- *
- * Results:
- * Returns a list as from passing the given statement to
- * Tdbc_TokenizeSql above.
- *
- *-----------------------------------------------------------------------------
- */
-
-MODULE_SCOPE int
-TdbcTokenizeObjCmd(
- ClientData clientData, /* Unused */
- Tcl_Interp* interp, /* Tcl interpreter */
- int objc, /* Parameter count */
- Tcl_Obj *const objv[] /* Parameter vector */
-) {
-
- Tcl_Obj* retval;
-
- /* Check param count */
-
- if (objc != 2) {
- Tcl_WrongNumArgs(interp, 1, objv, "statement");
- return TCL_ERROR;
- }
-
- /* Parse the statement */
-
- retval = Tdbc_TokenizeSql(interp, Tcl_GetString(objv[1]));
- if (retval == NULL) {
- return TCL_ERROR;
- }
-
- /* Return the tokenized statement */
-
- Tcl_SetObjResult(interp, retval);
- return TCL_OK;
-
-}
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