Bind variables are variables used in SQL statements, which are languages that perform writing and query to a database.
When making similar processing requests repeatedly while changing only a certain number to the database, if you re-set the number of the SQL statement each time, many types of SQL statements will be processed, which is inefficient. In such a case, if the bind variable is used, the database recognizes that “the same SQL statement is repeated processed under another condition”, so that the processing time can be efficiently improved and the processing time can be shortened.
In the case of Oracle Database, bind variables are represented by adding a colon(:) to the beginning of the variable name(e.g :number)
$sql = ‘select name, breed, weight from animals where weight > ? and weight < ?'; $conn = db2_connect($database, $user, $password); $stmt = db2_prepare($conn, $sql); $lower_limit = 1; db2_bind_param($stmt, 1, "lower_limit", DB2_PARAM_IN); db2_bind_param($stmt, 2, "upper_limit", DB2_PARAM_IN); $upper_limit = 15.0; if(db2_execute($stmt)){ while ($row = db2_fetch_array($stmt)){ print "{$row[0]}, {$row[1]}, {$row[2]}\n"; } } [/php]
