一种方法是使用Foreach循环逐个获取DataGridView中的所有行值，然后将它们插入。
mysql> DROP VIEW view_test6, view_test7; Query OK, 0 rows affected (0.01 sec) 1. 2. 3. 2、查看视图 view_test6 与视图 view_test7是否存在 mysql> #查看 view_test6 是否存在# mysql> SELECT * -> FROM view_test6; ERROR 1146 (42S02): Table 'view.view_test6' doesn't exist 1. 2...
I made quite a complex View on my MySQL database, and I realized that some queries are slow. My first idea was to add indexes but it's not possible to do on a view so I'm lost on how to improve the performance of my query. ...
MySqlConnectionconn=newMySqlConnection("server=localhost;database=mydatabase;uid=root;password=123456;");MySqlDataAdapteradapter=newMySqlDataAdapter("SELECT * FROM students",conn); 1. 2. 4. 填充数据到DataTable 使用数据适配器对象,我们可以将MySQL数据库中的数据填充到一个DataTable对象中,以便后续绑定到...
TABLE_CATALOG The name of the catalog to which the table or view used in the view definition belongs. This value is alwaysdef. TABLE_SCHEMA The name of the schema (database) to which the table or view used in the view definition belongs. ...
TheVIEW_TABLE_USAGEtable (available as of MySQL 8.0.13) provides access to information about tables and views used in view definitions. You can see information only for views for which you have some privilege, and only for tables for which you have some privilege. ...
FROMtable_name WHEREcondition; Note:A view always shows up-to-date data! The database engine recreates the view, every time a user queries it. MySQL CREATE VIEW Examples The following SQL creates a view that shows all customers from Brazil: ...
DataSet是存在于内存中的数据库,不依赖于数据库的独立数据集合,内部是用XML来描述数据的,需要与DataAdapter来填充数据。 DataView表示用于排序、筛选、搜索、编辑和排序的DataTable的可绑定数据的自定义视图。 本文使用以上三种方式做了一个实例: using MySql.Data.MySqlClient; ...
table 't2' === var/log/mysqld.2.err === ... [ERROR] Slave SQL: Query caused different errors on master and slave. Error on master: 'Table '%-.192s' already exists' (1050), Error on slave: 'View's SELECT refers to a temporary table 't2'' (1352). Default database: 'test'...
new MySqlConnection(connStr); mySqlConnection.Open(); //create DataSet Krant dataSet = new DataSet("DataSetName"); //set the dataAdapter for Country da["country"] = new MySqlDataAdapter("SELECT * FROM `country`;", this.mySqlConnection); //setup the table-schema for country da["country...