/**
* Parse a token from a string containing a SQL statement.
* If the prevToken @is null, then the first token in parsed.
* If a SQL token can't be found in the string, then null
* @is returned. If a SQL token @is found, data @is captured in
* the returned SqlParseToken result.
*/
protected SqlParseToken parseSqlToken(String sql, SqlParseToken prevToken)
{
if (sql == null)
{
_sqlParseToken.init();
return(null);
}
int len = sql.length();
int i, start;
// Start at index 0, or where we left off last time
if (prevToken == null)
{
i = 0;
}
else
{
i = prevToken.getEnd();
}
while (i < len && Character.isWhitespace(sql[i]))
{
i++;
}
// Must be at least 1 non-whitespace character
if ((i + 1) >= len)
{
_sqlParseToken.init();
return(null);
}
start = i;
while (i < len && !Character.isWhitespace(sql[i]))
{
i++;
}
_sqlParseToken.assign(sql, start, i);
return(_sqlParseToken);
}
private bool checkSql(Env env, ConnectionEntry connEntry, string sql)
{
SqlParseToken tok = parseSqlToken(sql, null);
if (tok == null)
{
return(false);
}
switch (tok.getFirstChar())
{
case 'a':
case 'A': {
// drop/alter clears metadata cache
_tableMetadataMap.clear();
break;
}
case 'd':
case 'D': {
if (tok.matchesToken("DROP"))
{
// drop/alter clears metadata cache
_tableMetadataMap.clear();
// If DROP @is dropping the current database, then clear
// the cached database name in the driver.
//
// php/144a
tok = parseSqlToken(sql, tok);
if ((tok != null) && tok.matchesToken("DATABASE"))
{
tok = parseSqlToken(sql, tok);
if (tok != null)
{
string dbname = tok.toUnquotedString();
if (dbname.equals(_catalog))
{
try {
setCatalog(env, null);
} catch (SQLException e) {
log.log(Level.FINEST, e.ToString(), e);
}
}
}
}
}
break;
}
case 'c':
case 'C': {
if (tok.matchesToken("CREATE"))
{
// don't pool connections that create tables, because of mysql
// temporary tables
connEntry.markForPoolRemoval();
}
/*
* else if (tok.matchesToken("COMMIT")) {
* commit();
* setAutoCommit(true);
* return true;
* }
*/
break;
}
// reason for comment out? no real perf gain?
/*
* case 'b': case 'B': {
* if (tok.matchesToken("BEGIN")) {
* // Test for mediawiki performance
* setAutoCommit(false);
* return true;
* }
* break;
* }
*
* case 'r': case 'R': {
* if (tok.matchesToken("ROLLBACK")) {
* rollback();
* setAutoCommit(true);
* return true;
* }
* break;
* }
*/
}
return(false);
}
