dbQueryPrepare#

Purpose#

Prepares a SQL query for execution.

Format#

ret = dbQueryPrepare(qid, query)#

Parameters:

qid (scalar) – query index number.
query (string) – database query to prepare.

Returns:

ret (scalar) – 1 for success and 0 for failure.

Examples#

// Add "MYSQL" database to list of database connections
db_id = dbAddDatabase("MYSQL");

// Create query
qid = dbCreateQuery(db_id);

// Prepare query
ret = dbQueryPrepare(qid, "SELECT *
    FROM STOCKS WHERE SYMBOL = :sym");

// Set `:sym` placeholder
dbQueryBindValue(qid, ":sym", "GOOG");

// Execute query
ret = dbQueryExecPrepared(qid);

Remarks#

The query may contain placeholders for binding values. Both Oracle style colon-name (e.g., :surname), and ODBC style (?) placeholders are supported; but they cannot be mixed in the same query.

Note

Portability: Some databases choose to delay preparing a query until it is executed the first time. In this case, preparing a syntactically incorrect query succeeds, but every consecutive dbQueryExecPrepared() will fail.

For SQLite, the query string can contain only one statement at a time. If more than one statement is given, the function returns 0.