List of functions in sqlx.inc

Function Description
SQL_MakeDbTuple
Creates a connection information tuple.
This tuple must be passed into connection routines.
Freeing the tuple is not necessary, but is a good idea if you
 create many of them.  You can cache these handles globally.
!!NOTE!! I have seen most people think that this connects to the DB.
  Nowhere does it say this, and in fact it does not.  It only caches
  the connection information, the host/user/pass/etc.

The optional timeout parameter specifies how long connections should wait before
giving up.  If 0, the default (which is undefined) is used.
SQL_FreeHandle
Frees an SQL handle.
The handle can be to anything (tuple, connection, query, results, etc).
If you free a database connection, it closes the connection as well.
SQL_Connect
Opens a database connection.
Returns an SQL handle, which must be freed.
Returns Empty_Handle on failure.
SQL_SetCharset
Sets the character set of the current connection.
Like SET NAMES .. in mysql, but stays after connection problems.

If a connection tuple is supplied, this should be called before SQL_Connect or SQL_ThreadQuery.
Also note the change will remain until you call this function with another value.

Example: "utf8", "latin1"
SQL_PrepareQuery
Prepares a query.
The query must always be freed.
This does not actually do the query!
SQL_QuoteString
Back-quotes characters in a string for database querying.
Note: The buffer's maximum size should be 2*strlen(string) to catch
all scenarios.
SQL_QuoteStringFmt
Back-quotes characters in a string for database querying.
Note: The buffer's maximum size should be 2*strlen(string) to catch
all scenarios.
SQL_ThreadQuery
Prepares and executes a threaded query.
This will not interrupt gameplay in the event of a poor/lossed
 connection, however, the interface is more complicated and
 asynchronous.  Furthermore, a new connection/disconnection is
 made for each query to simplify driver support.
The handler should look like:
SQL_Execute
Executes a query.
Returns 1 if the query succeeded.
Returns 0 if the query failed.
NOTE: You can call this multiple times as long as its parent
 connection is kept open.  Each time the result set will be freed
 from the previous call.
SQL_QueryError
Gets information about a failed query error.
Returns the errorcode.
SQL_MoreResults
Returns 1 if there are more results to be read,
 0 otherwise.
SQL_IsNull
Tells whether a specific column in the current row
 is NULL or not.
SQL_ReadResult
Retrieves the current result.
A successful query starts at the first result,
 so you should not call SQL_NextRow() first.
Passing no extra params - return int
Passing one extra param - return float in 1st extra arg
Passing two extra params - return string in 1st arg, max length in 2nd
Example:
 new num = SQL_ReadResult(query, 0)
 new Float:num2
 new str[32]
 SQL_ReadResult(query, 1, num2)
 SQL_ReadResult(query, 2, str, 31)
SQL_NextRow
Advances to the next result (return value should be ignored).
SQL_AffectedRows
Returns the number of affected rows.
SQL_NumResults
Returns the number of rows total.
SQL_NumColumns
Returns the number of columns total.
SQL_FieldNumToName
Returns the name of a column.
Errors on a bad field number.
SQL_FieldNameToNum
Returns the number of a named column, or -1 if not found.
SQL_Rewind
Rewinds a result set to the first row.
SQL_GetInsertId
Returns the insert id of the last INSERT query.
Returns 0 otherwise.
SQL_GetAffinity
Returns which driver this plugin is currently bound to.
SQL_SetAffinity
Sets driver affinity.  You can use this to force a particular
 driver implementation.  This will automatically change all SQL
 natives in your plugin to be "bound" to the module in question.
If no such module is found, it will return 0.  This isn't necessarily bad -
 the user might have typed the wrong driver.  Unless your plugin is built
 to handle different driver types at once, you should let this error pass.
Note, that using this while you have open handles to another database
 type will cause problems.  I.e., you cannot open a handle, switch
 affinity, then close the handle with a different driver.
Switching affinity is an O(n*m) operation, where n is the number of
 SQL natives and m is the number of used natives in total.
Intuitive programmers will note that this causes problems for threaded queries.
 You will have to either force your script to work under one affinity, or to
 pack the affinity type into the query data, check it against the current, then
 set the new affinity if necessary.  Then, restore the old for safety.
SQL_GetQueryString
Returns the original query string that a query handle used.
SQL_NextResultSet
For queries which return multiple result sets, this advances to the next
result set if one is available.  Otherwise, the current result set is
destroyed and will no longer be accessible.

This function will always return false on SQLite, and when using threaded
queries in MySQL.  Nonetheless, it has the same effect of removing the last
result set.
sqlite_TableExists
This function can be used to find out if a table in a Sqlite database exists.
(updated for newer API)
SQL_SimpleQuery
Use this for executing a query where you don't care about the result.
Returns 0 on failure, 1 on success
SQL_SimpleQueryFmt
Use this for executing a query where you don't care about the result.
Returns 0 on failure, 1 on success
SQL_QueryAndIgnore
Use this for executing a query and not caring about the error.
Returns -1 on error, >=0 on success (with number of affected rows)
SQL_MakeStdTuple
This function has no description.