Postgres if in select7/2/2023 If I run this it only reports the last database as opposed to both. How would I have this enclosed in a bash script so I can run this against each database. I want to run this query against multiple databases. I want the bash to run the script and if there is data i.e results then run and report (the reporting part works in terms of email etc)īut the select runs and there is 0 results then print/echo "No Values" if statement in select postgresql Code Answer. What I want to know is if the results return nothing could I have it so a message is at least inputted instead of (0 rows), even if it was just a message to say there are no Values or something to that extent. SELECT field1, field2, CASE WHEN field1>0 THEN field2/field1 ELSE 0 END AS field3 FROM test. I am running this in a bash script via psql however the results will be sent out in an email which I have working. I am running a select statement as below: select * from maxIDValue where max_value > 1000000 order by max_value desc Through practical examples, this post explained the working of Postgres ELSE IF statement.Have been trying to work out how to return a message if the result is empty. If none of the specified conditions retrieve a true value, then the statements associated with the else part will get executed. When a condition becomes true, all the statements associated with that condition will get executed, and the rest of the conditions will be skipped. It checks/evaluates each condition one by one. In Postgres, the ELSIF is one of the decision-driven statements that evaluate several conditions. If an expression doesn’t satisfy the specified criteria, then the if-statement moves the control to the next statement. Since the student having id 3 is a 19-year-old male, so, the ELSIF statement that satisfies the given condition retrieves a notice “Adult Male”. The syntax of the IF statement is as follows: IF condition THEN statement END IF Here, condition represents a criterion that must be satisfied to execute the statements specified within the THEN block. RAISE NOTICE 'Student with the specified id does not exist in the student_info table' IF student_data.std_age 18 AND student_data.std_gender= 'M' THENĮLSIF student_data.std_age 18 AND student_data.std_gender= 'F' THEN If none of the above-given conditions return true, then show a notice "student with the specified id doesn't exist in the student_info table".If std_age > 18 and std_gender = F then show “Adult Female”.If std_age 18 and std_gender = M then show “Adult Male”.Now we will specify the following five scenarios in the control statements: We have created a table named student_info and inserted the following records into it: SELECT * FROM student_info The output shows that the condition specified in the ELSIF part retrieves a true value, so the statement associated with the ELSIF part gets executed.Įxample #2: How to Use ELSIF Statement on Table’s Data? Else raise a notice “first_val is equal to the second_val”.In the if statement, we checked whether the first_val second_val then return “first_val is greater than second_val”.Afterward, we utilized conditional statements to compare their values: In this example, we created two variables named first_val and second_val. RAISE NOTICE 'first_val is equal to second_val' RAISE NOTICE 'first_val is greater than second_val' Statements //gets executed only if all the provided conditions retrieve false.Įxample #1: How to Use IF-THEN-ELSIF Statement in Postgres? Let’s create two variables and assign them some random values: DO $$ Statements //gets executed only if condition_n retrieves true. Statements //gets executed only if condition_2 retrieves true. Statements //gets executed only if condition_1 retrieves true. The below snippet elaborates the syntax of the IF-THEN-ELSIF statement: IF condition_1 THEN If none of the specified conditions retrieve a true value, then the statements associated with the else part will get executed.When a condition becomes true, all the statements associated with that condition will get executed, and the rest of the conditions will be skipped.The IF THEN ELSIF statement checks/evaluates each condition one by one.IF-THEN-ELSIF is one of the decision-driven statements that evaluate several conditions. How Does the ELSE IF Statement Work in PostgreSQL? This write-up will discuss the working of the IF-THEN-ELSIF statement through practical examples. In Postgres, the IF and IF-THEN-ELSE statements evaluate only one condition however, the IF-THEN-ELSIF statement evaluates several conditions. All these decision-driven statements are used to control the flow of the SQL statements based on specific criteria. PostgreSQL offers several decision-making statements such as IF, IF-THEN-ELSE, IF-THEN-ELSIF, etc.
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