To remove the primary key from a table use the following syntax. ALTERTABLECustomerDROPPRIMARYKEY With this command, the column is no longer used as a primary key. It doesnotdelete the column. Composite Keys # A composite key is a primary key which that consists of multiple columns. ...
alter table 表名 字段操作;:修改一张表的字段结构,操作如下: add column 字段名 数据类型:向已有的表结构添加一个字段。 add primary key(字段名):将某个字段声明为主键。 add foreing key 外键字段 表名.字段名:将一个字段设置为另一张表的外键。 add unique 索引名(字段名):为一个字段创建唯一索引。
# 提示在这个过程中需要重启GreatSQL-02节点实例 # 如果无法自动重启,需要手动重启 NOTE: A server restart is expected to happen as part of the clone process. If the server does not support the RESTART command or does not come back after a while, you may need to manually start it back. * ...
'{1}','{2}','{3}','{4}','{5}','{6}','{7}')",userLogin,userPass,userNicename,userEmail,userStatus,displayName,userUrl,userActivationKey);cmd=newSqlCommand(sql,conn);cmd.ExecuteNonQuery();}finally{///
SELECT wg.name AS workload_group_name, rp.name AS resource_pool_name, r.command, r.status, d.name AS database_name, COUNT(1) AS request_count, MIN(r.start_time) AS first_request_start_time, MAX(r.start_time) AS last_request_start_time, SUM(CAST(r.total_elapsed_ti...
Set conn = CreateObject("ADODB.Connection") conn.Open "Provider=SQLOLEDB;Data Source=MyServer;Database=tempdb;Integrated Security=SSPI" conn.Properties("SQLXML Version") = "sqlxml.4.0" Set cmd = CreateObject("ADODB.Command") Set stm = Creat...
(connectionString)) { using (SqlCommand cmd = new SqlCommand(commandText, conn)) { cmd.CommandType = commandType; cmd.Parameters.AddRange(parameters); conn.Open(); return cmd.ExecuteScalar(); } } } // Set the connection, command, and then execute the command with query and return the ...
// Specify the username parameter.command.Parameters.Add(newSqlParameter("@Username", userName));// Specify the password parameter.command.Parameters.Add(newSqlParameter("@Password", password));// Retrieve the number of matching records.introwCount = ...
BulkQuery db.Queryable<Order>().ToList();//Slightly faster than Dapper //Suitable for big data export List<Order> order = new List<Order>(); db.Queryable<Order>().ForEach(it=> { order.Add(it); } ,2000); 10.5 BulkDelete db.Deleteable<Order>(list).PageSize(1000).ExecuteCommand()...
NOTICE: Replica identity is neededforshard table, pleaseaddto this table through"alter table"command. CREATE TABLE 建立两个子表,分别存入“广东”和“北京” postgres=# create table t_list_gd partition of t_native_list(f1 ,f2 , f3,f4) for values in ('广东'); ...