table中的每一个entry被称为record. 一个table可以有多个records. intersection of a column and a record is a field. 10. insert into investigations(datasToSolve, title,detective) values(3, "The Missing Tree", "Finch Hosky"); // 插入一行数据时,指定字段名称,不和数据库表中的字段顺序一致的办法 ...
Commands: completion Generate the autocompletion script for the specified shell config Modify sqlconfig files using subcommands like "sqlcmd config use-context mssql" create Install/Create SQL Server, Azure SQL, and Tools delete Uninstall/Delete the current context help Help about any command open ...
show tables;show databases;show partitions;show functions;describe extended table_name dot col_name; DDL(Data Defination Language):数据库定义语言 建表: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 CREATE[EXTERNAL]TABLE[IFNOTEXISTS]table_name[(col_name data_type[COMMENTcol_comment],...)][...
Commands: completion Generate the autocompletion script for the specified shell config Modify sqlconfig files using subcommands like "sqlcmd config use-context mssql" create Install/Create SQL Server, Azure SQL, and Tools delete Uninstall/Delete the current context help Help about any command open ...
ExecuteNonQuery Executes commands such as Transact-SQL INSERT, DELETE, UPDATE, and SET statements. ExecuteScalar Retrieves a single value (for example, an aggregate value) from a database. ExecuteXmlReader Sends the CommandText to the Connection and builds an XmlReader object. You can reset the Co...
CREATE(DATABASE|SCHEMA)[IFNOTEXISTS]database_name[COMMENTdatabase_comment][LOCATIONhdfs_path][MANAGEDLOCATIONhdfs_path][WITHDBPROPERTIES(property_name=property_value,...)]; LOCATION 是指定外部表的存储路径,MANAGEDLOCATION 是指定管理表的存储路径(hive 4.0.0 才支持),官方建议默认就行,让所有的表都在一...
(parameterName, i)); batch.BatchCommands.Add(batchCommand); } // Optionally Prepare batch.Prepare(); var results = new List<int>(count); using (SqlDataReader reader = batch.ExecuteReader()) { do { while (reader.Read()) { results.Add(reader.GetFieldValue<int>(0)); } } while (...
Data types, SQL commands SQL varchar data type deep dive May 29, 2019 by Gauri Mahajan In this article we’ll review the SQL varchar data type including a basic definition and overview, differences from varchar(n), UTF-8 support, Collation, performance considerations and more. Data types...
For example, you can create a user calledmigrationswith the minimum required privileges required to migrate a database by using the following commands: CREATE USER migrations IDENTIFIED BYpasswordDEFAULT TABLESPACE users TEMPORARY TABLESPACE temp; GRANT CONNECT, RESOURCE, CREATE VIEW, CREATE PUBLIC SYNONY...
A table can have three triggers, one for each of the commands that can modify data in a table: the UPDATE, INSERT, and DELETE commands. The trigger is automatically executed when the command is carried out. The Upsizing Wizard uses triggers rather th...