The columns of the join tables can be different for JOIN, but for UNION the number of columns and the column order of all queries must be the same.
How do you join the two tables with different columns?
Simply put, JOINs combine data by adding the columns of one table to the columns of another table. In contrast, UNIONS combine data by appending the rows next to rows from another table. Note the following when using UNION in SQL: All SELECT statements must list the same number of columns.
How to join different columns in different tables in SQL?
Three main ways to combine data
- JOIN – You can use joins to combine columns from one or more queries into a single result.
- UNION – Use unions and other set operators to combine rows from one or more queries into a single result.
Can you join multiple columns in SQL?
5 answers. Yes: you can use inner join to join multiple columns.
How to join two tables in different columns in MySQL?
A: Joining two tables in SQL can be done in four ways: Inner Join (returns rows with matching columns), Left Join (ALL records from left table and matching records from right table), Right Join (ALL records in the right table and matching records in the left table) and union (removes duplicates).
How to combine two selected queries in SQL with different number of columns?
Use the UNION ALL clause to join data from columns in two or more tables. In our example, we are merging data from the employee and customer tables. Place the first SELECT statement to the left of the UNION ALL keyword to retrieve data from the first table (the employees table in our example).
How to join two tables in SQL?
To join two tables based on a column match without losing data from the left table, you would use a LEFT OUTER JOIN. Left outer joins are used when you want to get all the values from a table, but only the records matching the left table from the right table. 17
How can I get multiple columns from multiple tables in SQL?
Syntax example for selecting from multiple tables:
- SELECT p. p_id, p. cus_id, p. name_p, c1. name1, c2. name2.
- DES product AS p.
- LEFT JOIN Customer1 AS c1.
- A p. cus_id=c1. cus_id.
- LEFT JOIN customer2 AS c2.
- A p. cus_id = c2. cus_id.
How to join three tables on different columns in SQL?
Join 3 tables with a join table
- The first step is to look at the schema and select the columns that we want to show. …
- The next step is to determine which tables are needed for the query. …
- In the last part all the tables have to be put together.