Executing a stored procedure over ODBC
I have an application that allows the user to enter an SQL string with a placeholder for certain values my application produces. The application will the replace the placeholders with values and execute the SQL string through various database backends.
For the ODBC backend, I call SQLExe开发者_运维问答cDirect() on the SQL strin which works nicely on regular queries, but fails for stored procedures with parameters.
Is there a simple way to extend this mechanism to support stored procedures ? A certain way how the SQL must be written ?
The only thing I can think of right now is to start parsing the SQL string and call SQLBindParameter() n times if it conatains a "call". But parsing SQL is tricky.
Any ideas ?
Working SQL example: SELECT columnA from foo where columnB = '%placeholder'
Non-working SQL: CALL StoredFoo('%placeholder')
How to call stored procedures (ODBC):
To run a procedure as an RPC
Construct a SQL statement that uses the ODBC CALL escape sequence. The statement uses parameter markers for each input, input/output, and output parameter, and for the procedure return value (if any):
{? = CALL procname (?,?)}
Call SQLBindParameter for each input, input/output, and output parameter, and for the procedure return value (if any).
Execute the statement with
SQLExecDirect
.
Otherwise you need to execute the procedure as an ordinary batch (not an RPC call), ie. you need to run the batch:
EXEC procname @param1, @param2, @param3...;
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