SELECTFirstName,LastName,OrderCount=(SELECTCOUNT(O.id)FROM[Order]OWHEREO.CustomerId=C.Id)FROMCustomer C Try it live This is called acorrelated subquerybecause the subquery references the enclosing query, specifically, the C.Id in the WHERE clause. ...
The expression can't be a subquery or contain alias data types. Computed columns can be used in select lists, WHERE clauses, ORDER BY clauses, or any other locations in which regular expressions can be used, with the following exceptions: Computed columns must be marked PERSISTED to ...
OPENXML <openxml_clause> Applies to: SQL Server and SQL Database. Provides a rowset view over an XML document. For more information, see OPENXML (Transact-SQL). derived_table A subquery that retrieves rows from the database. derived_table is used as input to the outer query. derived_...
Subquery A subquery is a SQL statement that has another SQL query embedded in the WHERE or the HAVING clause. SyntaxThe syntax for a subquery when the embedded SQL statement is part of the WHERE condition is as follows:SELECT "column_name1" FROM "table_name1" WHERE "column_name2" [...
SQLWithSubqueryClause withSubQuery; SQLSelectQuery query; } interface SQLSelectQuery extends SQLObject {} class SQLSelectQueryBlock implements SQLSelectQuery { List<SQLSelectItem> selectList; SQLTableSource from; SQLExpr where; SQLSelectGroupByClause groupBy; ...
Query hints can be specified only in the top-level query, not in subqueries. When a table hint is specified as a query hint, the hint can be specified in the top-level query or in a subquery. However, the value specified...
For the examples below we are using theAdventureWorks2014 database. Download a copy and restore to your instance of SQL Server to test the below scripts. Using a Subquery in a SQL Server SELECT Statement WHERE Clause One of the most common places to invoke a subquery is in the WHERE claus...
SELECT Clause_1 INTERSECT SELECT Clause_2; MySQL中可以通过IN和子查询来间接实现INTERSECT的功能: SELECT col_1, col_2, col_3 FROM table_a AS a WHERE (a.col_1, a.col_2, a.col_3) IN (SELECT b.col_1, b.col_2, b.col_3 FROM table_b AS b); 4.3 EXCEPT/EXCEPT ALL EXCEPT对两个...
Query hints can be specified only in the top-level query, not in subqueries. When a table hint is specified as a query hint, the hint can be specified in the top-level query or in a subquery. However, the value specified forexposed_object_namein theTABLE HINTclause must match exactly ...
Here are several other examples to illustrate the extensive possibilities of theGROUP BYclause. Example 10.12. What is the average total amount of penalties for players who live in Stratford and Inglewood? SELECT AVG(TOTAL) FROM (SELECT PLAYERNO, SUM(AMOUNT) AS TOTAL ...