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UNION Syntax. SELECT column_name (s) FROM table1. UNION. SELECT column_name (s) FROM table2; UNION ALL Syntax. The UNION operator selects only distinct values by default. To allow duplicate values, use UNION ALL: SELECT column_name (s) FROM table1. UNION ALL. SELECT column_name (s) FROM table2;
UNION combines the result from multiple SELECT statements into a single result set. Example: mysql> SELECT 1, 2; . +---+---+. | 1 | 2 |. +---+---+. | 1 | 2 |. +---+---+. mysql> SELECT 'a', 'b'; . +---+---+. | a | b |. +---+---+. | a | b |. +---+---+. mysql> SELECT 1, 2 UNION SELECT 'a', 'b'; . +---+---+. | 1 | 2 |. +---+---+. | 1 | 2 |.
The UNION operator is a set operator that combines result sets of two or more SELECT statements into a single result set. The following illustrates the syntax of the UNION operator that combines the result sets of two queries: SELECT column_list_1 FROM T1 UNION SELECT column_list_1 FROM T2; Code language: SQL (Structured Query Language) (sql)
UNION combines the result from multiple SELECT statements into a single result set. Example: mysql> SELECT 1, 2; . +---+---+. | 1 | 2 |. +---+---+. | 1 | 2 |. +---+---+. mysql> SELECT 'a', 'b'; . +---+---+. | a | b |. +---+---+. | a | b |. +---+---+. mysql> SELECT 1, 2 UNION SELECT 'a', 'b'; . +---+---+. | 1 | 2 |. +---+---+. | 1 | 2 |.
8 Σεπ 2008 · The UNION ALL command is equal to the UNION command, except that UNION ALL selects all values. The difference between Union and Union all is that Union all will not eliminate duplicate rows, instead it just pulls all rows from all tables fitting your query specifics and combines them into a table.
17 Μαΐ 2023 · The syntax of MySQL UNION operator. Rules and restrictions of MySQL UNION. MySQL UNION vs. JOIN. MySQL UNION vs. UNION ALL. Practical examples and use cases. Example 1: Basic UNION. Example 2: UNION ALL. Example 3: UNION with a condition. Example 4: UNION with DISTINCT. Example 5: Simple UNION for keyword search.
UNION: Combine all results from two query blocks into a single result, omitting any duplicates. INTERSECT: Combine only those rows which the results of two query blocks have in common, omitting any duplicates.
