Restrictions on subquery use, including performance issues for Section 8.2.2, “Optimizing Subqueries, Derived Tables, View References, and Common Table WHERE b > ANY (VALUES ROW(2), ROW(4), ROW(6)) Ī subquery's outer statement can be any one of:įor information about how the optimizer handles subqueries, see Ts VALUES ROW(2), ROW(4), ROW(6), the statements shown Versions of subqueries that can be rewritten more compactly using There are few restrictions on the type of statements in which
Often can be used only in certain contexts, as described in the Subqueries that return a particular kind of result These are called scalar, column, row, and table
Single column, or a table (one or more rows of one or moreĬolumns). (SELECT 50,11*s1 FROM t4 UNION SELECT 50,77 FROMĪ subquery can return a scalar (a single value), a single row, a Subquery syntax as specified by the SQL standard and supported in Here is an example statement that shows the major points about Gave people the original idea of calling the early SQL Indeed, it was the innovation of subqueries that This SQL query will return a single result set with two columns, containing values from columns a and b in table1. For example: SELECT a, b FROM table1 UNION SELECT c, d FROM table2. The UNION keyword lets you execute one or more additional SELECT queries and append the results to the original query. Many people find subqueries more readable than complex joins This results in a SQL injection UNION attack. Otherwise require complex joins and unions. They provide alternative ways to perform operations that would That it is possible to isolate each part of a statement. They allow queries that are structured so Query, and in fact it is possible to nest subqueries within other SELECT * FROM t1 WHERE column1 = (SELECT column1 FROM t2) WHERE IS NOT NULL Īnd of course, you must apply the same method to this part, too.13.2.15.1 The Subquery as Scalar Operand 13.2.15.2 Comparisons Using Subqueries 13.2.15.3 Subqueries with ANY, IN, or SOME 13.2.15.4 Subqueries with ALL 13.2.15.5 Row Subqueries 13.2.15.6 Subqueries with EXISTS or NOT EXISTS 13.2.15.7 Correlated Subqueries 13.2.15.8 Derived Tables 13.2.15.9 Lateral Derived Tables 13.2.15.10 Subquery Errors 13.2.15.11 Optimizing Subqueries 13.2.15.12 Restrictions on SubqueriesĪll subquery forms and operations that the SQL standard requiresĪre supported, as well as a few features that are MySQL-specific. Plus, you'll need to end each query with, like this: SELECT AS ordine, AS data, comm AS commessa So you have to wrap the right part of the UNION with (). I found a simple solution: myODBC will only understand queries with ONE UNION (or UNION ALL). It's a MyODBC bug see offical entry here. SELECT AS ordine, AS data, numero AS commessa SELECT AS ordine, AS data, comm AS commessa WHERE `numero ordine cliente` IS NOT NULLĮdit, if you are using MS Access then you will need to use the square brackets: SELECT * SELECT `numero ordine cliente` AS ordine, `data ordine cliente` AS data, numero AS commessa So I think your query should be: SELECT `Ordine numero` AS ordine, `data ordine` AS data, comm AS commessa The identifier quote character is the backtick (“`”): So if you need to enclose table/column name use backticks `. As far as I know, square brackets are not valid for MySQL and are only valid for Microsoft products (SQL Server/MS Access). You have tagged your question as MySQL and you are using square brackets.
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