mysql_query
Send a MySQL query
Description
resourcemysql_query
stringquery
resourcelink_identifier
intresult_mode
mysql_query sends a query to the currently
active database on the server that's associated with the
specified link identifier. If
link_identifier isn't specified, the last
opened link is assumed. If no link is open, the function tries
to establish a link as if mysql_connect was
called with no arguments, and use it.
The optional result_mode parameter
can be MYSQL_USE_RESULT and MYSQL_STORE_RESULT. It
defaults to MYSQL_STORE_RESULT, so the result is buffered.
See also mysql_unbuffered_query for the
counterpart of this behaviour.
The query string should not end with a semicolon.
Only for SELECT,SHOW,EXPLAIN or DESCRIBE statements
mysql_query
returns a resource identifier or &false; if the query was
not executed correctly. For other type of SQL statements,
mysql_query returns &true; on success
and &false; on error. A non-&false; return value
means that the query was legal and could be executed by
the server. It does not indicate anything about the number of
rows affected or returned. It is perfectly possible for a query
to succeed but affect no rows or return no rows.
The following query is syntactically invalid, so
mysql_query fails and returns &false;:
mysql_query
]]>
The following query is semantically invalid if
my_col is not a column in the table
my_tbl, so mysql_query
fails and returns &false;:
mysql_query
]]>
mysql_query will also fail and return &false;
if you don't have permission to access the table(s) referenced by
the query.
Assuming the query succeeds, you can call
mysql_num_rows to find out how many rows
were returned for a SELECT statment or
mysql_affected_rows to find out how many
rows were affected by a DELETE, INSERT, REPLACE, or UPDATE
statement.
Only for SELECT,SHOW,DESCRIBE or EXPLAIN statements,
mysql_query
returns a new result identifier that you can pass to
mysql_fetch_array and other
functions dealing with result tables. When you are done with the
result set, you can free the resources associated with it by
calling mysql_free_result. Although, the
memory will automatically be freed at the end of the script's
execution.
See also: mysql_num_rows,
mysql_affected_rows,
mysql_unbuffered_query,
mysql_free_result,
mysql_fetch_array,
mysql_fetch_row,
mysql_fetch_assoc,
mysql_result,
mysql_select_db, and
mysql_connect.