4 rows in set (0.00 sec) NULL is the SQL value for "no value";任何一个字段都可能是NULL,只要你不给他赋值! 12. select title, detective from investigations; // 只选择部分字段 13. data types: varchar(100) create table person(name varchar(100)); text create table email(body text); Numb...
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 ...
DBCC SHRINKDATABASE: 缩小数据库文件以释放未使用的空间。 sqlCopy Code DBCCSHRINKDATABASE('MyDatabase'); DBCC SHRINKFILE: 缩小特定数据文件或日志文件以释放未使用的空间。 sqlCopy Code DBCCSHRINKFILE('MyDatabase_Log',100); -- 缩小日志文件到100MB DBCC UPDATEUSAGE: 更新系统表中存储空间使用的信息。
active transactions, run these commands:'ASRecommendation;SELECT'DBCC OPENTRAN ('+QUOTENAME(@dbname) +')'ASFindOpenTran;SELECT'SELECT database_id, db_name(database_id) AS dbname, database_transaction_begin_time, database_transaction_state, database_transaction_log_record_count, ...
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 ...
Always back up your data before performing any modifications to the database. If possible, test any alter, insert, update, or delete SQL commands on a staging server first. The following SQL has not been tested in Confluence 5.7 and above create table TEMP...
sqlps Utility Used to run PowerShell commands and scripts. Loads and registers the SQL Server PowerShell provider and cmdlets. <drive>:\Program Files\Microsoft SQL Server\nnn\Tools\Binn sqlservr Application Used to start and stop an instance of Database Engine from the command prompt for troubl...
shrinkingmydb, the Database Engine calculates the target size for the data file to be 8 MB (6 MB of data plus 2 MB of free space). As such, the Database Engine moves any data from the data file's last 2 MB to any free space in the data file's first 8 MB and then shrinks ...
SqlCommandfeatures the following methods for executing commands at a SQL Server database: 展开表 You can reset theCommandTextproperty and reuse theSqlCommandobject. However, you must close theSqlDataReaderbefore you can execute a new or previous command. ...
TiDB - the open-source, cloud-native, distributed SQL database designed for modern applications. - pingcap/tidb