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How to join different tables depending on column value?
So, if in P.type is ‘C’ it represents a table named C, if the value is ‘D’ it represents a table named D. Now I want to have a SELECT statement which gives me values from table C or D respectively, depending on P.type.
Which is an example of inner join in SQL?
Let us take an example of the inner join. ON A. Common_COLUMN =B. Common_COLUMN b) LEFT JOIN: Left Join gets all the rows from the Left table and common rows of both tables. Let us take an example of the left join.
How to do left join and right join in SQL?
1. Left Join Left Join = All rows from left table + INNER Join Let us consider two tables and apply Left join on the tables: – Query to get the loan_no, status, and borrower date from two tables: – Let’s check the output of the above table after applying the Left join on them. 2. RIGHT Join
What do you need to join two tables in SQL?
As mentioned earlier joins are used to get data from more than one table. To join more than one table we need at least one column common in both tables. Tables get joined based on the condition specified. This is a guide to SQL Join Two Tables.
What happens if I have to join table d?
If I have to join table D the returned columns (resultset) shall be as it is but if table C must be joined, a further column shall be returned. Hence, the SELECT clause changes from
How to insert values into table from two different tables?
If I was given teacher’s name ( david for example) and student_id ( 7 for example) and asked to insert the teacher_id into the classroom table based on the id in the teachers table, I would do : Now, what if I was not given the student’s id directly and given only the name of the student?
When to use two left join s in SQL?
(Enough information is present to ‘know’ which table to join on.) If the two tables vary significantly enough to make the UNION ALL impractical, then using two LEFT JOIN s may be you best option.