| Function | Description
|
| mysql_affected_rows() | Returns the number of rows changed/deleted/inserted
by the last UPDATE, DELETE, or INSERT query.
|
| mysql_change_user() | Changes user and database on an open connection.
|
| mysql_charset_name() | Returns the name of the default character set for
the
connection.
|
| mysql_close() | Closes a server connection.
|
| mysql_connect() | Connects to a MySQL server. This function is deprecated;
use mysql_real_connect() instead.
|
| mysql_create_db() | Creates a database. This function is deprecated; use
the
SQL statement CREATE DATABASE instead.
|
| mysql_data_seek() | Seeks to an arbitrary row number in a query result set.
|
| mysql_debug() | Does a DBUG_PUSH with the given string.
|
| mysql_drop_db() | Drops a database. This function is deprecated; use the
SQL
statement DROP DATABASE instead.
|
| mysql_dump_debug_info() | Makes the server write debug information to the
log.
|
| mysql_eof() | Determines whether the last row of a result set has been
read.
This function is deprecated; mysql_errno() or mysql_error() may be used
instead.
|
| mysql_errno() | Returns the error number for the most recently invoked
MySQL
function.
|
| mysql_error() | Returns the error message for the most recently invoked
MySQL function.
|
| mysql_escape_string() | Escapes special characters in a string for use in
an
SQL statement.
|
| mysql_fetch_field() | Returns the type of the next table field.
|
| mysql_fetch_field_direct() | Returns the type of a table field, given a
field number.
|
| mysql_fetch_fields() | Returns an array of all field structures.
|
| mysql_fetch_lengths() | Returns the lengths of all columns in the current
row.
|
| mysql_fetch_row() | Fetches the next row from the result set.
|
| mysql_field_seek() | Puts the column cursor on a specified column.
|
| mysql_field_count() | Returns the number of result columns for the most
recent statement.
|
| mysql_field_tell() | Returns the position of the field cursor used for the
last mysql_fetch_field().
|
| mysql_free_result() | Frees memory used by a result set.
|
| mysql_get_client_info() | Returns client version information as a string.
|
| mysql_get_client_version() | Returns client version information as an
integer.
|
| mysql_get_host_info() | Returns a string describing the connection.
|
| mysql_get_server_version() | Returns version number of server as an integer
(new in 4.1).
|
| mysql_get_proto_info() | Returns the protocol version used by the
connection.
|
| mysql_get_server_info() | Returns the server version number.
|
| mysql_info() | Returns information about the most recently executed query.
|
| mysql_init() | Gets or initializes a MYSQL structure.
|
| mysql_insert_id() | Returns the ID generated for an AUTO_INCREMENT column
by
the previous query.
|
| mysql_kill() | Kills a given thread.
|
| mysql_list_dbs() | Returns database names matching a simple regular
expression.
|
| mysql_list_fields() | Returns field names matching a simple regular
expression.
|
| mysql_list_processes() | Returns a list of the current server threads.
|
| mysql_list_tables() | Returns table names matching a simple regular
expression.
|
| mysql_num_fields() | Returns the number of columns in a result set.
|
| mysql_num_rows() | Returns the number of rows in a result set.
|
| mysql_options() | Sets connect options for mysql_connect().
|
| mysql_ping() | Checks whether the connection to the server is working,
reconnecting as necessary.
|
| mysql_query() | Executes an SQL query specified as a null-terminated
string.
|
| mysql_real_connect() | Connects to a MySQL server.
|
| mysql_real_escape_string() | Escapes special characters in a string for use
in an SQL statement, taking into account the current charset of the
connection.
|
| mysql_real_query() | Executes an SQL query specified as a counted string.
|
| mysql_reload() | Tells the server to reload the grant tables.
|
| mysql_row_seek() | Seeks to a row offset in a result set, using value
returned from mysql_row_tell().
|
| mysql_row_tell() | Returns the row cursor position.
|
| mysql_select_db() | Selects a database.
|
| mysql_set_server_option() | Sets an option for the connection (like multi
-statements).
|
| mysql_sqlstate() | Returns the SQLSTATE error code for the last error.
|
| mysql_shutdown() | Shuts down the database server.
|
| mysql_stat() | Returns the server status as a string.
|
| mysql_store_result() | Retrieves a complete result set to the client.
|
| mysql_thread_id() | Returns the current thread ID.
|
| mysql_thread_safe() | Returns 1 if the clients are compiled as thread-safe.
|
| mysql_use_result() | Initiates a row-by-row result set retrieval.
|
| mysql_warning_count() | Returns the warning count for the previous SQL
statement.
|
| mysql_commit() | Commits the transaction.
|
| mysql_rollback() | Rolls back the transaction.
|
| mysql_autocommit() | Toggles autocommit mode on/off.
|
| mysql_more_results() | Checks whether any more results exist.
|
| mysql_next_result() | Returns/Initiates the next result in multi-query
executions.
|
To connect to the server, call mysql_init() to initialize a connection
handler, then call mysql_real_connect() with that handler (along with other
information such as the hostname, username, and password). Upon connection,
mysql_real_connect() sets the reconnect flag (part of the MYSQL structure)
to a value of 1. This flag indicates, in the event that a query cannot be
performed because of a lost connection, to try reconnecting to the server
before giving up. When you are done with the connection, call mysql_close()
to terminate it.
While a connection is active, the client may send SQL queries to the server
using mysql_query() or mysql_real_query(). The difference between the two
is
that mysql_query() expects the query to be specified as a null-terminated
string whereas mysql_real_query() expects a counted string. If the string
contains binary data (which may include null bytes), you must use
mysql_real_query().
For each non-SELECT query (for example, INSERT, UPDATE, DELETE), you can
find out how many rows were changed (affected) by calling
mysql_affected_rows().
For SELECT queries, you retrieve the selected rows as a result set. (Note
that some statements are SELECT-like in that they return rows. These
include
SHOW, DESCRIBE, and EXPLAIN. They should be treated the same way as SELECT
statements.)
There are two ways for a client to process result sets. One way is to
retrieve the entire result set all at once by calling mysql_store_result().
This function acquires from the server all the rows returned by the query
and stores them in the client. The second way is for the client to initiate
a row-by-row result set retrieval by calling mysql_use_result(). This
function initializes the retrieval, but does not actually get any rows from
the server.
In both cases, you access rows by calling mysql_fetch_row(). With
mysql_store_result(), mysql_fetch_row() accesses rows that have already
been
fetched from the server. With mysql_use_result(), mysql_fetch_row()
actually
retrieves the row from the server. Information about the size of the data
in
each row is available by calling mysql_fetch_lengths().
After you are done with a result set, call mysql_free_result() to free the
memory used for it.
The two retrieval mechanisms are complementary. Client programs should
choose the approach that is most appropriate for their requirements. In
practice, clients tend to use mysql_store_result() more commonly.
An advantage of mysql_store_result() is that because the rows have all been
fetched to the client, you not only can access rows sequentially, you can
move back and forth in the result set using mysql_data_seek() or
mysql_row_seek() to change the current row position within the result set.
You can also find out how many rows there are by calling mysql_num_rows().
On the other hand, the memory requirements for mysql_store_result() may be
very high for large result sets and you are more likely to encounter out-of
-memory conditions.
An advantage of mysql_use_result() is that the client requires less memory
for the result set because it maintains only one row at a time (and because
there is less allocation overhead, mysql_use_result() can be faster).
Disadvantages are that you must process each row quickly to avoid tying up
the server, you don't have random access to rows within the result set (you
can only access rows sequentially), and you don't know how many rows are in
the result set until you have retrieved them all. Furthermore, you must
retrieve all the rows even if you determine in mid-retrieval that you've
found the information you were looking for.
The API makes it possible for clients to respond appropriately to queries
(retrieving rows only as necessary) without knowing whether or not the
query
is a SELECT. You can do this by calling mysql_store_result() after each
mysql_query() (or mysql_real_query()). If the result set call succeeds, the
query was a SELECT and you can read the rows. If the result set call fails,
call mysql_field_count() to determine whether a result was actually to be
expected. If mysql_field_count() returns zero, the query returned no data
(indicating that it was an INSERT, UPDATE, DELETE, etc.), and was not
expected to return rows. If mysql_field_count() is non-zero, the query
should have returned rows, but didn't. This indicates that the query was a
SELECT that failed. See the description for mysql_field_count() for an
example of how this can be done.
Both mysql_store_result() and mysql_use_result() allow you to obtain
information about the fields that make up the result set (the number of
fields, their names and types, etc.). You can access field information
sequentially within the row by calling mysql_fetch_field() repeatedly, or
by
field number within the row by calling mysql_fetch_field_direct(). The
current field cursor position may be changed by calling mysql_field_seek().
Setting the field cursor affects subsequent calls to mysql_fetch_field().
You can also get information for fields all at once by calling
mysql_fetch_fields().
For detecting and reporting errors, MySQL provides access to error
information by means of the mysql_errno() and mysql_error() functions.
These
return the error code or error message for the most recently invoked
function that can succeed or fail, allowing you to determine when an error
occurred and what it was.