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The UNION ALL command combines the result set of two or more SELECT statements (allows duplicate values). The following SQL statement returns the cities (duplicate values also) from both the "Customers" and the "Suppliers" table: Example. SELECT City FROM Customers. UNION ALL. SELECT City FROM Suppliers. ORDER BY City; Try it Yourself »
Jun 3, 2024 · SQL UNION ALL command combines the result of two or more SELECT statements in SQL. For performing the UNION ALL operation, it is necessary that both the SELECT statements should have an equal number of columns/fields otherwise the resulting expression will result in an error.
May 28, 2021 · You can use SQL’s UNION and UNION ALL commands to get data from multiple tables in your database. It’s a common use case, considering that most databases have many tables. Both UNION and UNION ALL are known as set operators. In SQL, set operators combine the results of two or more queries into a single result.
The UNION operator combines result sets of two or more SELECT statements into a single result set. The following statement illustrates how to use the UNION operator to combine result sets of two queries: SELECT . column1, column2. FROM . table1 . UNION [ ALL ] SELECT . column3, column4. FROM .
Jan 5, 2023 · Example #1 - UNION. Renaming Columns in UNION. Example #2 - Using the Same Number of Columns in UNION. Example #3 - UNION ALL. UNION vs. UNION ALL – Choosing Which to Use. In this article, we’ll explore the SQL clauses UNION and UNION ALL. Learn what they do and when to use each one.
This SQL tutorial explains how to use the SQL UNION ALL operator with syntax and examples. The SQL UNION ALL operator is used to combine the result sets of 2 or more SELECT statements (does not remove duplicate rows).
UNION ALL Operator is used to combine result set of two or more SELECT queries. The UNION ALL operator does not remove duplicate rows from SELECT statement result set. UNION and UNION ALL operators works same. Only difference is UNION operator exclude duplicate rows from result set. UNION ALL does not remove duplicate rows from query result set.
We can use the UNION ALL operator to combine the results of two SELECT statements that select data from these two tables: SELECT id, name, age, NULL AS subject. FROM students. UNION ALL. SELECT id, name, NULL AS age, subject. FROM teachers;
Jun 3, 2024 · SQL UNION and UNION ALL operators are used to concatenate results of multiple SELECT statements. However, they are different from each other. One key difference between UNION and UNION ALL in SQL is that the UNION command removes duplicates from the final results set, whereas the UNION ALL command allows duplicates in the results set.
May 23, 2023 · The following are basic rules for combining the result sets of two queries by using UNION: The number and the order of the columns must be the same in all queries. The data types must be compatible. Transact-SQL syntax conventions. Syntax. syntaxsql. Copy. { <query_specification> | ( <query_expression> ) } . { UNION [ ALL ] .
