How to refer to another table in a CASE WHEN Statement in PostGIS?

Can we use case statement in where clause in PostgreSQL?

CASE expression can be used anywhere, such as SELECT, WHERE, GROUP BY, and HAVING clauses, where we compare two values.
Jun 29, 2021

How does case statement work in PostgreSQL?

Introduction to PostgreSQL CASE



Each condition is a boolean expression and based on its output the result is chosen. If all the expressions corresponding to WHEN are evaluated to be False , then the result respective to the ELSE part is shown. In case, you don’t specify the ELSE part; the query will return null.

How to use case in select statement in SQL Server?

The CASE expression goes through conditions and returns a value when the first condition is met (like an if-then-else statement). So, once a condition is true, it will stop reading and return the result. If no conditions are true, it returns the value in the ELSE clause.

Are table names in Postgres case sensitive?

PostgreSQL names are case sensitive. By default, AWS Schema Conversion Tool (AWS SCT) uses object name in lowercase for PostgreSQL. In most cases, you’ll want to use AWS Database Migration Service transformations to change schema, table, and column names to lower case.

Can you put WHERE in CASE statement?

CASE can be used in any statement or clause that allows a valid expression. For example, you can use CASE in statements such as SELECT, UPDATE, DELETE and SET, and in clauses such as select_list, IN, WHERE, ORDER BY, and HAVING.
Nov 18, 2022

How to add two conditions in case statement in PostgreSQL?

Here are 3 different ways to apply a case statement using SQL:

1. (1) For a single condition: CASE WHEN condition_1 THEN result_1 ELSE result_2 END AS new_field_name.
2. (2) For multiple conditions using AND: CASE WHEN condition_1 AND condition_2 THEN result_1 ELSE result_2 END AS new_field_name.

Which is the correct format for case statement?

SQL Case Statement Syntax



After that comes the keyword THEN and the value for that condition, like WHEN THEN . This can then be followed by other WHEN / THEN statements. At the end you can add a value to use by default if none of the conditions are true with the ELSE keyword, as shown below.
Aug 16, 2021

How do you write a case statement in Shell?

The case statement starts with the case keyword followed by the $variable and the in keyword. The statement ends with the case keyword backwards – esac . The script compares the input $variable against the patterns in each clause until it finds a match.
Dec 15, 2021

Can we add CASE statement in WHERE clause in SQL?

The CASE statement returns the value based on condition. We can use a case statement in Where, Order by and Group by clause. In the Customer table, I have displayed the First Name is Ram or the Last Name is Sharma’s salary. So, by using a CASE statement with the where condition displays the result.

Can I use CTE in WHERE clause?

Using the CTE –



After you define your WITH clause with the CTEs, you can then reference the CTEs as you would refer any other table.
Sep 23, 2021

Which of the following Cannot be used in WHERE clause?

Answer: C. A column alias cannot be used in WHERE clause conditions but can be used in SELECT statement and ORDER BY clause.