PHP's mssql_fetch_row, mssql_fetch_array, mssql_fetch_assoc and mssql_fetch_objcect read data

require 'dbconn.php';
$sql = 'select * from _Test';
$query = mssql_query($sql);
while($row=mssql_fetch_row($query))
{
echo $row['UserId'].'::'.$row[1].'';
}

Return: Notice: Undefined index: UserId in D:/_PHP_Test/Test2/test_connLocalDB.php on line 32 ::王小一 Notice: Undefined index: UserId in D:/_PHP_Test/Test2/test_connLocalDB.php on line 32 ::王小儿 Notice: Undefined index: UserId in D:/_PHP_Test/Test2/test_connLocalDB.php on line 32 ::王小三 Notice: Undefined index: UserId in D:/_PHP_Test/Test2/test_connLocalDB.php on line 32 ::王小思 Notice: Undefined index: UserId in D:/_PHP_Test/Test2/test_connLocalDB.php on line 32 ::王小五

Analysis: mssql_fetch_row() is exactly the same as using mssql_fetch_array() plus the second optional parameter MYSQL_NUM. Gets a row of data from the result set associated with the specified result identifier and returns it as an array. Each result column is stored in a cell of the array, starting at offset 0. Note that the offset here starts from 0, and the key value (field name) cannot be used to obtain the value, only the index can be used to obtain the value. Therefore, the value cannot be obtained using $row['key value'] here.

2. Method name: mssql_fetch_assoc() Example:

$query = mssql_query($sql);
while($row=mssql_fetch_assoc($query))
{
echo $row['UserId'].'::'.$ row[1].'';
}

Return: Notice: Undefined offset: 1 in D:/_PHP_Test/Test2/test_connLocalDB.php on line 43 1:: Notice: Undefined offset: 1 in D:/_PHP_Test/Test2/test_connLocalDB.php on line 43 2:: Notice: Undefined offset: 1 in D:/_PHP_Test/Test2/test_connLocalDB.php on line 43 3:: Notice: Undefined offset: 1 in D:/_PHP_Test/Test2/test_connLocalDB.php on line 43 4:: Notice: Undefined offset: 1 in D:/_PHP_Test/Test2/test_connLocalDB.php on line 43 5:: analyze: mssql_fetch_assoc() is exactly the same as mssql_fetch_array() plus the second optional parameter MYSQL_ASSOC. It just returns an associative array. This is also how mssql_fetch_array() initially works. Therefore, the value cannot be obtained using $row[index value].

3. Method name: mssql_fetch_array() Example:

$query = mssql_query($sql);
while($row=mssql_fetch_array($query))
{
echo $row['UserId'].'::'.$ row[1].'';
}
?>

Return: 1::Wang Xiaoyi 2::Wang Xiaoer 3::Wang Xiaosan 4::Wang Xiaosi 5::Wang Xiaowu

Analysis: mssql_fetch_array() is an extended version of mssql_fetch_row(). In addition to storing data in an array as a numerical index, you can also store data as an associative index, using the field name as the key. Therefore, both $row['key value'] and $row[index value] can be used here to get the value.

The second parameter result_type (this is a constant) in mssql_fetch_array() is an optional parameter, and the value range is: MYSQL_ASSOC, MYSQL_NUM and MYSQL_BOTH. in: mssql_fetch_array($query, MYSQL_ASSOC) == mssql_fetch_assoc($query); mssql_fetch_array($query, MYSQL_NUM) == mssql_fetch_row($query); Therefore, the mssql_fetch_array() function can be regarded as a collection of mssql_fetch_row() and mssql_fetch_assoc () to a certain extent. Therefore, mssql_fetch_array() also has the MYSQL_BOTH parameter and will get an array containing both associations and numeric indexes.

4. Method name: mssql_fetch_object() Example:

$query=mssql_query($sql);
while($row=mssql_fetch_object($query))
{
echo $row->UserId.'::'.$row ->CreateTime."";
}

Return: 1::06 7 2011 4:46PM 2::06 7 2011 4:46PM 3::06 7 2011 4:46PM 4::06 7 2011 4:46PM 5::06 7 2011 4:46PM

Analysis: mysql_fetch_object() is similar to mssql_fetch_array, with one difference, that is, it returns an object instead of an array, and uses the field name as an attribute. Indirectly also means that it can only be accessed by the field name, not the offset.