Luckily, SQL makes selecting multiple columns from a table easy. To select multiple columns from a table, simply separate the column names with commas! Selecting specific columns For example, this query selects two columns, name and birthdate, from the people table: SELECT name, birthdate FROM...
COUNT() function and SELECT with DISTINCT on multiple columns You can use the count() function in a select statement with distinct on multiple columns to count the distinct rows. Here is an example: SELECT COUNT(*) -- Count the number of rows in the result set FROM ( SELECT DISTINCT age...
SELECTID , Name , (SELECTMAX(LastUpdateDate)FROM(VALUES( UpdateByApp1Date), ( UpdateByApp2Date), ( UpdateByApp3Date) )ASUpdateDate ( LastUpdateDate ) )ASLastUpdateDateFROM##TestTable 方法二 SELECTID ,[Name],MAX(UpdateDate)ASLastUpdateDateFROM##TestTable UNPIVOT ( UpdateDateFORDateValIN(...
microsoftml.select_columns(cols: [list, str], **kargs) 说明 选择一组要重新定型的列,删除所有其他列。 参数 cols 要保留的字符串或变量名称列表。 kargs 发送到计算引擎的其他参数。 返回 一个定义转换的对象。 请参阅 concat,drop_columns.
mysql> select distinct tiny_column from big_table limit 2; mysql> -- Returns the unique combinations of values from multiple columns. mysql> select distinct tiny_column, int_column from big_table limit 2; distinct可以和聚合函数(通常是count函数)一同使用,count(disitnct)用于计算出一个列或多个...
)ASLastUpdateDateFROM##TestTable name列相同的话,是无法得出name分组之后的最大值,这里要注意一下 转载自:https://www.mssqltips.com/sqlservertip/4067/find-max-value-from-multiple-columns-in-a-sql-server-table/ MySQL 5.7 OCP MySQL 8.0 OCP 3...
问题原因:Hologres不支持使用SELECT INTO语法。 解决方法:您可使用INSERT INTO SELECT方式插入数据,详情请参见INSERT。 报错:ALTER TABLE CHANGE OWNER is not supported in SLPM (Schema-Level Permission Mode) 问题原因:不支持在SLPM模型下使用ALTER TABLE的方式改变表Owner。
使用CREATE EXTERNAL TABLE建立外部數據表。 location 使用LOCATION和ALTER TABLE的CREATE TABLE子句來設定數據表位置。 owner 使用[SET] OWNER TO和ALTER TABLE的ALTER VIEW語句來轉移表或檢視的擁有權。 SET 在 Databricks SQL 中可做為選擇性關鍵詞。 provider ...
select @accountdeptname=USER_DEPT_NAME from USER_DEPT where USER_DEPT_ID=@accountdeptid select @superiordeptname=USER_DEPT_NAME from USER_DEPT where USER_DEPT_ID=@superiordeptid if @state=1 begin select @accountname=USERNAME from RIGHTS_USERS where USERID=@accountuserid ...
error occurs if you try to add a new row with a key value that matches an existing row. If you specify a prefix value for a column in a UNIQUE index, the column values must be unique within the prefix length. A UNIQUE index permits multiple NULL values for columns that can contain ...