|
|
db2_bind_param
Binds a PHP variable to an SQL statement parameter
Description
bool db2_bind_param
( resource $stmt
, int $parameter-number
, string $variable-name
[, int $parameter-type
[, int $data-type = 0
[, int $precision = -1
[, int $scale = 0
]]]] )
Parameters
-
stmt
-
A prepared statement returned from db2_prepare.
-
parameter-number
-
Specifies the 1-indexed position of the parameter in the prepared
statement.
-
variable-name
-
A string specifying the name of the PHP variable to bind to the
parameter specified by parameter-number.
-
parameter-type
-
A constant specifying whether the PHP variable should be bound to the
SQL parameter as an input parameter (DB2_PARAM_IN),
an output parameter (DB2_PARAM_OUT), or as a
parameter that accepts input and returns output
(DB2_PARAM_INOUT). To avoid memory overhead, you can
also specify DB2_PARAM_FILE to bind the PHP variable
to the name of a file that contains large object (BLOB, CLOB, or DBCLOB)
data.
-
data-type
-
A constant specifying the SQL data type that the PHP variable should be
bound as: one of DB2_BINARY,
DB2_CHAR, DB2_DOUBLE, or
DB2_LONG .
-
precision
-
Specifies the precision with which the variable should be bound to the
database. This parameter can also be used for retrieving XML output values
from stored procedures. A non-negative value specifies the maximum size of
the XML data that will be retrieved from the database. If this parameter
is not used, a default of 1MB will be assumed for retrieving the XML
output value from the stored procedure.
-
scale
-
Specifies the scale with which the variable should be bound to the
database.
Return Values
Returns TRUE on success or FALSE on failure.
Examples
Example #1 Binding PHP variables to a prepared statement
The SQL statement in the following example uses two input parameters in
the WHERE clause. We call db2_bind_param to bind two
PHP variables to the corresponding SQL parameters. Notice that the PHP
variables do not have to be declared or assigned before the call to
db2_bind_param; in the example,
$lower_limit is assigned a value before the call to
db2_bind_param, but $upper_limit
is assigned a value after the call to
db2_bind_param. The variables must be bound and, for
parameters that accept input, must have any value assigned, before calling
db2_execute.
<?php
$sql = 'SELECT name, breed, weight FROM animals
WHERE weight > ? AND weight < ?';
$conn = db2_connect($database, $user, $password);
$stmt = db2_prepare($conn, $sql);
// We can declare the variable before calling db2_bind_param()
$lower_limit = 1;
db2_bind_param($stmt, 1, "lower_limit", DB2_PARAM_IN);
db2_bind_param($stmt, 2, "upper_limit", DB2_PARAM_IN);
// We can also declare the variable after calling db2_bind_param()
$upper_limit = 15.0;
if (db2_execute($stmt)) {
while ($row = db2_fetch_array($stmt)) {
print "{$row[0]}, {$row[1]}, {$row[2]}\n";
}
}
?>
The above example will output:
Pook, cat, 3.2
Rickety Ride, goat, 9.7
Peaches, dog, 12.3
Example #2 Calling stored procedures with IN and OUT parameters
The stored procedure match_animal in the following example accepts
three different parameters:
-
an input (IN) parameter that accepts the name of the first animal as
input
-
an input-output (INOUT) parameter that accepts the name of the second
animal as input and returns the string TRUE if an
animal in the database matches that name
-
an output (OUT) parameter that returns the sum of the weight of the
two identified animals
In addition, the stored procedure returns a result set consisting of the
animals listed in alphabetic order starting at the animal corresponding
to the input value of the first parameter and ending at the animal
corresponding to the input value of the second parameter.
<?php
$sql = 'CALL match_animal(?, ?, ?)';
$conn = db2_connect($database, $user, $password);
$stmt = db2_prepare($conn, $sql);
$name = "Peaches";
$second_name = "Rickety Ride";
$weight = 0;
db2_bind_param($stmt, 1, "name", DB2_PARAM_IN);
db2_bind_param($stmt, 2, "second_name", DB2_PARAM_INOUT);
db2_bind_param($stmt, 3, "weight", DB2_PARAM_OUT);
print "Values of bound parameters _before_ CALL:\n";
print " 1: {$name} 2: {$second_name} 3: {$weight}\n\n";
if (db2_execute($stmt)) {
print "Values of bound parameters _after_ CALL:\n";
print " 1: {$name} 2: {$second_name} 3: {$weight}\n\n";
print "Results:\n";
while ($row = db2_fetch_array($stmt)) {
print " {$row[0]}, {$row[1]}, {$row[2]}\n";
}
}
?>
The above example will output:
Values of bound parameters _before_ CALL:
1: Peaches 2: Rickety Ride 3: 0
Values of bound parameters _after_ CALL:
1: Peaches 2: TRUE 3: 22
Results:
Peaches, dog, 12.3
Pook, cat, 3.2
Rickety Ride, goat, 9.7
Example #3 Inserting a binary large object (BLOB) directly from a file
The data for large objects are typically stored in files, such as XML
documents or audio files. Rather than reading an entire file into a PHP
variable, and then binding that PHP variable into an SQL statement, you
can avoid some memory overhead by binding the file directly to the input
parameter of your SQL statement. The following example demonstrates how
to bind a file directly into a BLOB column.
<?php
$stmt = db2_prepare($conn, "INSERT INTO animal_pictures(picture) VALUES (?)");
$picture = "/opt/albums/spook/grooming.jpg";
$rc = db2_bind_param($stmt, 1, "picture", DB2_PARAM_FILE);
$rc = db2_execute($stmt);
?>
|