PHP4 and MySQL database operation functions (3)

7) database information functions (2 ):
1. mysql_fetch_field ()
Format: object mysql_fetch_field (int query, int [field_offset]);
Returns an object, that is, a hash table marked:
Table: table name
Name: Field name
Max_length: maximum length of the field
Not_null: If the field is not null, 1 is returned; otherwise, 0 is returned.
Primary_key: If the field is primary key, 1 is returned; otherwise, 0 is returned.
Unique_key: If the field is unique key, 1 is returned; otherwise, 0 is returned.
Multiple_key: If the field is not a unique key, 1 is returned; otherwise, 0 is returned.
Numeric: If the field is numeric, 1 is returned; otherwise, 0 is returned.
Blob: If the field is blob, 1 is returned; otherwise, 0 is returned.
Type: field type
Unsigned: If the field is unsigned, 1 is returned; otherwise, 0 is returned.
Zerofill: If the field is zero filled, 1 is returned; otherwise, 0 is returned.
Reference format: Object name-> subscript name
You can use this function to obtain the table name, field name, and type .......
Example:
$ Query = mysql_query ($ SQL, $ connect );
While ($ object = mysql_fetch_field ($ query ))
{
Echo "table name:". $ object-> table ."
";
Echo "field name:". $ object-> name ."
";
Echo "primary key:". $ object-> primary_key ."
";
Echo "not null:". $ object-> not_null ."
";
Echo "field type:". $ object-> type ."
";
Echo "field max length:". $ object-> max_length ."
";
}
?>
Note: the hash table starts with 0 coordinates, that is, the first field is 0 items in the hash table.
If you want to directly obtain the information of the third field in the hash table, the format is as follows:
$ Query = mysql_query ($ SQL, $ connect );
$ Object = mysql_fetch_field ($ query, 2 );
Echo "table name:". $ object-> table ."
";
Echo "field name:". $ object-> name ."
";
Echo "primary key:". $ object-> primary_key ."
";
Echo "not null:". $ object-> not_null ."
";
Echo "field type:". $ object-> type ."
";
Echo "field max length:". $ object-> max_length ."