generate_dynamic_id('my_sequence_id_s', 'my_table_t', 'table_id', @dynamicId);

Should be:

CALL generate_dynamic_id('my_sequence_id_s', 'my_table_t', 'table_id', 
@dynamicId);

PB

----

On 1/4/2011 9:28 PM, James Dekker wrote:
Hello there,

I am using MySQL 5 on OS X - Snow Leopard...

Have working code in place which obtains the highest sequence number ID from a 
sequence table and then increments and assigns it to its corresponding table:

The original code's purpose is to dynamically increments a specific table's 
last sequence id and set its corresponding table's id to that new value.

Notes:

-------------------------------------------------------------

(1) Original Code Snippet (which is working):

-- Get last sequence number.
replace into my_sequence_id_s set id = (select max(CONVERT(sequence_id, 
signed)) from my_table_t);

-- Increments the number.
insert into my_sequence_id_s set id = null;

-- Saves the number as a variable
set @dynamicId = last_insert_id();

-- Print
select @dynamicId;

-------------------------------------------------------------

(2) Refactoring:

DROP PROCEDURE IF EXISTS generate_dynamic_id#
CREATE PROCEDURE generate_dynamic_id(IN _sequence_table varchar(40),IN 
_actual_table varchar(40), IN _id_field VARCHAR(40), OUT dynamic_id varchar(40))
BEGIN
   -- Get Last Sequence Number
   set @getLastSequenceNumberSQL = concat('REPLACE INTO ', _sequence_table, 
'SET ID = (select max(CONVERT(',_id_field,', signed)) from ', _actual_table, 
');');
   prepare lastRecordStmt from @getLastSequenceNumberSQL;
   execute lastRecordStmt;
   deallocate prepare lastRecordStmt;

   -- Increments the number.
   set @createNewSequenceNumberSQL = concat('insert into ', _sequence_table ,' 
set id = null;');
   prepare newSequenceNumberStmt from @createNewSequenceNumberSQL;
   execute newSequenceNumberStmt;
   deallocate prepare newSequenceNumberStmt;

   -- Set the number as a dynamic variable.
   set @dynamic_id = last_insert_id();
END;
#

-------------------------------------------------------------

(3) Here's the calling function (which fails):

-- Get dynamically incremented id
generate_dynamic_id('my_sequence_id_s', 'my_table_t', 'table_id', @dynamicId);

Error:

com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: You have an error in your 
SQL syntax; check the manual that corresponds to your MySQL server version
for the right syntax to use near 'generate_dynamic_id('my_sequence_id_s', 
'my_table_t', 'table_id', @dyn' at line 1.

-------------------------------------------------------------

For some odd reason, dynamic function calls are not allowed in Stored Functions 
or Triggers, so that's why a Stored Procedure was used.

As you can see, I am setting up varchars at the parameters and then trying to 
concatenate them as strings and run them inside prepared statements.

Any help would be greatly appreciated...

-James

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