PHP中的常用的25个MYSQL函数.doc
PHP中的常用的25个MYSQL函数1、mysql_connect()-建立数据库连接格式：resource mysql_connect(string hostname :port :/path/to/socket , string username , string password)例：$conn = mysql_connect(”localhost”, “username”, “password”) or die(”不能连接到Mysql Server”);说明：使用该连接必须显示的关闭连接2、mysql_pconnect()-建立数据库连接格式：resource mysql_pconnect(string hostname :port :/path/to/socket , string username , string password)例：$conn = mysql_pconnect(”localhost”, “username”, “password”) or dir(”不能连接到Mysql Server”);说明：使用该连接函数不需要显示的关闭连接，它相当于使用了连接池3、mysql_close()-关闭数据库连接例：$conn = mysql_connect(”localhost”, “username”, “password”) or die(”不能连接到Mysql Server”);mysql_select_db(”MyDatabase”) or die(”不能选择这个数据库，或数据库不存在”);echo “你已经连接到MyDatabase数据库”;mysql_close();4、mysql_select_db()-选择数据库格式：boolean mysql_select_db(string db_name , resource link_id)例：$conn = mysql_connect(”localhost”, “username”, “password”) or die(”不能连接到Mysql Server”);mysql_select_db(”MyDatabase”) or die(”不能选择这个数据库，或数据库不存在”);5、mysql_query()-查询MySQL格式：resource mysql_query (string query, resource link_id)例：$linkId = mysql_connect(”localhost”, “username”, “password”) or die(”不能连接到Mysql Server”);mysql_select_db(”MyDatabase”) or die(”不能选择这个数据库，或者数据库不存在”);$query = “select * from MyTable”;$result = mysql_query($query);mysql_close();说明：若SQL查询执行成功，则返回资源标识符，失败时返回FALSE。若执行更新成功，则返回TRUE，否则返回FALSE6、mysql_db_query()-查询MySQL格式：resource mysql_db_query(string database, string query , resource link_id)例：$linkId = mysql_connect(”localhost”, “username”, “password”) or die(”不能连接到MysqlServer”);$query = “select * from MyTable”;$result = mysql_db_query(”MyDatabase”, $query);mysql_close();说明：为了使代码清晰，不推荐使用这个函数调用7、mysql_result()-获取和显示数据格式：mixed mysql_result (resource result_set, int row , mixed field)例：$query = “select id, name from MyTable order by name”;$result = mysql_query($query);for($count=0;$count<=mysql_numrows($result);$count+) $c_id = mysql_result($result, 0, “id”); $c_name = mysql_result($result, 0, “name”); echo $c_id,$c_name;说明：最简单、也是效率最低的数据获取函数8、mysql_fetch_row()-获取和显示数据格式：array mysql_fetch_row (resource result_set)例：$query = “select id, name from MyTable order by name”;$result = mysql_query($query);while (list($id, $name) = mysql_fetch_row($result) echo(”Name: $name ($id) <br />”);说明：函数从result_set中获取整个数据行，将值放在一个索引数组中。通常会结使list()函数使用9、mysql_fetch_array()-获取和显示数据格式：array mysql_fetch_array (resource result_set , int result_type)例：$query = “select id, name from MyTable order by name”;$result = mysql_query($query);while($row = mysql_fetch_array($result, MYSQL_ASSOC) $id = $row"id" $name = $row"name" echo “Name: $name ($id) <br />”;又例：$query = “select id, name from MyTable order by name”;$result = mysql_query($query);while($row = mysql_fetch_array($result, MYSQL_NUM) $id = $row0; $name = $row; echo “Name: $name ($id) <br />”;说明：result_type的值有：MYSQL_ASSOC: 字段名表示键，字段内容为值MYSQL_NUM: 数值索引数组，操作与mysql_fetch_ros()函数一样MYSQL_BOTH: 即作为关联数组又作为数值索引数组返回。result_type的默认值。10、mysql_fetch_assoc()-获取和显示数据格式：array mysql_fetch_assoc (resource result_set)相当于调用 mysql_fetch_array(resource, MYSQL_ASSOC);11、mysql_fetch_object()-获取和显示数据格式：object mysql_fetch_object(resource result_set)例：$query = “select id, name from MyTable order by name”;while ($row = mysql_fetch_object($result) $id = $row->id; $name = $row->name; echo “Name: $name ($id) <br />”;说明：返回一个对象，在操作上与mysql_fetch_array()相同12、mysql_num_rows()-所选择的记录的个数格式：int mysql_num_rows(resource result_set)例：query = “select id, name from MyTable where id > 65;$result = mysql_query($query);echo “有”.mysql_num_rows($result).”条记录的ID大于65;说明：只在确定select查询所获取的记录数时才有用。13、mysql_affected_rows()受Insert,update,delete影响的记录的个数格式：int mysql_affected_rows(resource link_id)例：$query = “update MyTable set name=CheneyFu where id>=5;$result = mysql_query($query);echo “ID大于等于5的名称被更新了的记录数：”.mysql_affected_rows();说明：该函数获取受INSERT,UPDATE或DELETE更新语句影响的行数14、mysql_list_dbs()-获取数据库列表信息格式：resource mysql_list_dbs(resource link_id)例：mysql_connect(”localhost”, “username”, “password”);$dbs = mysql_list_dbs();echo “Databases: <br />”;while (list($db) = mysql_fetch_rows($dbs) echo “$db <br />”;说明：显示所有数据库名称15、mysql_db_name()-获取数据库名格式：string mysql_db_name(resource result_set, integer index)说明：该函数获取在mysql_list_dbs()所返回result_set中位于指定index索引的数据库名16、mysql_list_tables()-获取数据库表列表格式：resource mysql_list_tables(string database , resource link_id)例：mysql_connect(”localhost”, “username”, “password”);$tables = mysql_list_tables(”MyDatabase”);while (list($table) = mysql_fetch_row($tables) echo “$table <br />”;说明：该函数获取database中所有表的表名17、mysql_tablename()-获取某个数据库表名格式：string mysql_tablename(resource result_set, integer index)例：mysql_connect(”localhost”, “username”, “password”);$tables = mysql_list_tables(”MyDatabase”);$count = -1;while (+$count < mysql_numrows($tables) echo mysql_tablename($tables, $count).”<br />”;说明：该函数获取mysql_list_tables()所返回result_set中位于指定index索引的表名18、mysql_fetch_field()-获取字段信息格式：object mysql_fetch_field(resource result , int field_offset)例：mysql_connect(”localhost”, “username”, “password”);mysql_select_db(”MyDatabase”);$query = “select * from MyTable”;$result = mysql_query($query);$counts = mysql_num_fields($result);for($count = 0; $count < $counts; $count+) $field = mysql_fetch_field($result, $count); echo “<p>$field->name $field->type ($field->max_length) </p>”;说明：返回的对象共有12个对象属性：name: 字段名table: 字段所在的表max_length: 字段的最大长度not_null: 如果字段不能为null，则为1，否则0primary_key: 如果字段为主键，则为1，否则0unique_key: 如果字段是唯一键，则为1， 否则0multiple_key: 如果字段为非唯一，则为1，否则0numeric: 如果字段为数值则为1，否则0blob: 如果字段为BLOB则为1，否则为0type: 字段的数据类型unsigned: 如果字段为无符号数则为1，否则为0zerofill: 如果字段为“零填充”则为1， 否则为019、mysql_num_fields()-获取查询的字段个数格式：integer mysql_num_fields (resource result_set)例：$query = “select id, name from MyTable order by name”;$result = mysql_query($query);echo “这个查询的字段数是：”.mysql_num_fields($result).”<br />”;20、mysql_list_fields()-获取指定表的所有字段的字段名格式：resource mysql_list_fields (string database_name, string table_name , resource link_id)例：$fields = mysql_list_fields(”MyDatabase”, “MyTable”);echo “数据库MyDatabase中表MyTable的字段数： “.mysql_num_fields($fields).”<br />”;21、mysql_field_flags()-获取指定的字段选项格式：string mysql_field_flags (resource result_set, integer field_offset)例：$query = “select id, name from MyTable order by name”;$result = mysql_query($query);$row=mysql_fetch_wor($row);22、mysql_field_len()-获取指定的字段的最大长度格式：integer mysql_field_len (resource result_set, integer field_offset)例：$query = “select name from MyTable”;$result = mysql_query($query);$row = mysql_fetch_row($result);echo mysql_field_len($result, 0).”<br />”;说明：如果mysql_field_len($reseult, 0) = 那么numer_format(mysql_field_len($result)等于16,777,21523、mysql_field_name()-获取字段名格式：string mysql_field_name (resource result_set, int field_offset)例：$query = “select id as PKID, name from MyTable order by name”;$result = mysql_query($query);$row = mysql_fetch_row($result);echo mysql_field_name($result, 0); / Result: PKID24、mysql_field_type()-获取字段类型格式：string mysql_field_type (resource result_set, int field_offset)例：$query = “select id, name from MyTable order by name”;$result = mysql_query($query);$row = mysql_fetch_row($result);echo mysql_field_type($result, 0); / Result: int25、mysql_field_table()-获取字段所在表名格式：string mysql_field_table (resource result_set, int field_offset)例：$query = “select id as PKID, name from MyTable order by name”;$result = mysql_query($query);$row = mysql_fetch_row($result);echo mysql_field_table($result, 0); / Result: MyTable
