MariaDB Check If Rows Exists [With 11 real examples]

In this MariaDB tutorial, we will discuss the MariaDB Check If Rows Exists statement and will look at several examples. There are lists of the topic that comes under discussion:

• MariaDB Check If Rows Exists
• MariaDB Check If Rows Exists By Name
• MariaDB Check If Rows Exists Count
• MariaDB Check If Rows Exists Distinct
• MariaDB Check If Rows Exists Group By
• MariaDB Check If Rows Exist Having
• MariaDB Check If Rows Exists Order By
• MariaDB Check If Rows Exists Json
• MariaDB Check If Rows Exists Multiple Columns
• MariaDB Check If Rows Exists Primary Key
• MariaDB Check If Rows Exists Temporary Table
• MariaDB Check If Rows Exists With Null

MariaDB Check If Rows Exists

Here we will understand how to use the MariaDB EXISTS statement which is used to check rows that exist in the query. And it’s explained with the help of an example.

To check whether rows exist in the table, we use the EXISTS condition in MariaDB. The EXISTS condition is used only in a subquery. It returns TRUE if the row exists in the table otherwise then FALSE is returned. In the MariaDB EXISTS condition, the TRUE is represented in 1, and FALSE is described in the form of 0.

First, we create a table called USA_PROGRAMMING_CLASS by the following query:

CREATE TABLE USA_PROGRAMMING_CLASS	
        STUDENT_ID INT AUTO_INCREMENT PRIMARY KEY,
	SITES_NAME VARCHAR(50),
	TOTAL_STUDENT  INT,
	CONSTRAINT POSITIVE_TOTAL_STUDENT
	CHECK(TOTAL_STUDENT > 0)
);

INSERT INTO USA_PROGRAMMING_CLASS (SITES_NAME, TOTAL_STUDENT ) VALUES 
 ('google.co.jp', 80),
 ('macromedia.com', 31),
 ( 'ucoz.ru', 99),
 ('hostgator.com', 64),
 ('bluehost.com', 11),
 ('seesaa.net', 19),
 ('boston.com', 9),
 ('constantcontact.com', 87),
 ('wp.com', 88),
 ('domainmarket.com', 4);
 
SELECT * FROM USA_PROGRAMMING_CLASS; 

In the first query, we first created a table called USA_PROGRAMMING_CLASS table by using the CREATE TABLE statement. Then we inserted some new records in the USA_PROGRAMMING_CLASS table by using the INSERT INTO statement.

We use the SELECT statement to retrieve all records from the USA_PROGRAMMING_CLASS table.

First, let’s see the syntax of the MariaDB EXISTS condition to check if the row exists in the table by the following query:

SYNTAX:

SELECT EXISTS(SELECT * FROM TABLE_NAME WHERE [CONDITION]);

Here is an illustrated example of the MariaDB Check If Rows Exists in the below following query:

SELECT EXISTS(SELECT * FROM USA_PROGRAMMING_CLASS WHERE STUDENT_ID=5) AS EXIST_CONDITION;

In this query, we have used the SELECT EXISTS statement with a subquery of the SELECT statement. In the subquery, the SELECT statement retrieves one record from the USA_PROGRAMMING_CLASS table with the WHERE condition.

In the WHERE condition, it will check the STUDENT_ID column is equal to 5 if the condition is TRUE.

Then the SELECT EXISTS condition will retrieve the result as TRUE which is in the form of 1 in the output.

Here we have understood how to use the MariaDB SELECT EXISTS statement for checking if a row exists in the table.

Read: MariaDB Insert Multiple Rows

MariaDB Check If Row Exists By Name

Here we will understand how to use the MariaDB EXISTS statement on the name column and check if the row exists in the query. And it is explained with the help of a demonstrated example.

EXAMPLE:

SELECT EXISTS (SELECT * FROM usa_programming_class 
WHERE WEB_SITES_NAME LIKE '%m') AS EXISTS_BY_NAME;

In the preceding query, we used the EXISTS statement on the subquery. In the INNER SELECT statement, we retrieve all records from the USA_PROGRAMMING_CLASS table with the WHERE condition.

In the WHERE condition, the WEB_SITES_NAME column will record rows whose name ends with the alphabet ‘m’. If it retrieves all records from the USA_PROGRAMMING_CLASS table, then the outer query of the SELECT EXISTS statement will be also executed.

And it will return the output value as 1 in the form of TRUE. If the EXISTS statement returns 0 as the output value then the query brings a FALSE result.

In this sub-topic, we have understood how to use the MariaDB EXISTS statement on the NAME column.

Read: MariaDB Greatest Function

MariaDB Check If Rows Exists Count

In this sub-topic, we will discuss and learn how to use the MariaDB EXISTS statement with the COUNT clause in the query and which is explained with the help of an illustrated example.

In MariaDB, the COUNT function is used to count the number of rows in the expression or column_name. Here is a sample example of the EXISTS statement with the COUNT clause in the below following query:

EXAMPLE:

SELECT EXISTS (SELECT COUNT(*) FROM usa_programming_class) AS EXISTS_BY_NAME;

As we see in the above query, we have used the EXISTS statement on the subquery. In the INNER SELECT statement, we retrieve all records from the USA_PROGRAMMING_CLASS table with the WHERE condition.

In the WHERE condition, the COUNT clause is used to count all records from the USA_PROGRAMMING_CLASS table then the SELECT EXISTS statement will retrieve the output result as 1 in the result set.

And it will return the output value as 1 in the form of TRUE. If the EXISTS statement returns 0 as the output value then the query brings a FALSE result.

in this section, we have understood the use of the MariaDB EXISTS statement with the COUNT function in the query.

Read: MariaDB Between + Examples

MariaDB Check If Rows Exists Distinct

Here we’ll use the MariaDB EXISTS statement with the DISTINCT clause in the query and which is explained with the help of an illustrated example.

In MariaDB, the DISTINCT clause is used to remove duplicate values from the SELECT statement. Now, let’s see an example of the MariaDB EXISTS statement on the DISTINCT clause by the following query:

EXAMPLE:

SELECT EXISTS(SELECT DISTINCT(WEB_SITES_NAME) FROM USA_PROGRAMMING_CLASS)
AS EXISTS_DISTINCT_CLAUSE;

In the preceding query, we used the SELECTS EXISTS statement on the subquery. In the INNER SELECT statement, we have used the DISTINCT clause on the WEB_SITES_NAME column from the USA_PROGRAMMING_CLASS table. The main use of the DISTINCT clause is to remove duplicate records from the WEB_SITES_NAME column.

So, as the INNER SELECT gets executed then the outer query of the SELECT EXISTS statement will return the output as 1 in the form of a TRUE result. But if the INNER SELECT gets a FALSE result then the outer query of the SELECT EXISTS statement will return the output as 0 in the form of a FALSE result.

We have also used the alias clause with AS keyword to shorter the name of the MariaDB EXISTS statement and the output column name is EXISTS_DISTINCT_CLAUSE.

In this sub-topic, we have used the MariaDB EXISTS statement with the DISTINCT clause which is used to check if a row exists in the table.

Read: MariaDB Drop Index + Examples

MariaDB Check If Rows Exists Group By

In this sub-topic, we will learn and understand how to use the MariaDB EXISTS statement with the GROUP BY clause in the query. And it is explained with the help of a sample example.

The group by clause in MariaDB divides a result’s rows into categories. The aggregate functions count(), min(), max(), sum(), and avg() are frequently used with the group by function to obtain attributes of groups.

For example, the number of elements (count), the total of values (sum), the maximum element (max), the minimum element (min), and the average of elements (avg).

Let’s have a look at the example of the MariaDB EXISTS statement with the GROUP BY clause in the below query:

EXAMPLE:

SELECT EXISTS (SELECT * FROM USA_PROGRAMMING_CLASS
GROUP BY WEBSITE_NAME) AS EXISTS_GROUP_BY;

In this query, we have used the SELECT EXISTS statement on the subquery. In the INNER SELECT statement, we retrieve all records from the USA_PROGRAMMING_CLASS table and grouped them based on the WEB_SITES_NAME column.

At the end of the query, we have used the alias clause as EXISTS_GROUP_BY for the output column. The main use of using the alias clause is to shorter the whole query.

Once the subquery gets executed then the EXISTS statement will return the value as 1 in the form of TRUE. But if the EXISTS statement gives a FALSE result then it will return 0 for the output result set.

Here we have understood how to use the MariaDB EXISTS statement with the GROUP BY clause which used was to find and check if the row exists in the query.

Read: MariaDB Queries

MariaDB Check If Rows Exists Having

In this MariaDB tutorial, we will use the MariaDB EXISTS statement with the HAVING clause in the query. There is a demonstrated example of explaining it in detail.

The MariaDB HAVING clause is used in conjunction with the GROUP BY clause to limit the returned rows to those that meet the condition. Let’s see an example of the MariaDB EXISTS statement with the HAVING clause by the following query:

EXAMPLE:

SELECT EXISTS(SELECT * FROM USA_PROGRAMMING_CLASS
GROUP BY WEB_SITES_NAME
HAVING MAX(STUDENT_ID) >5) AS EXISTS_HAVING_CLAUSE;

In the preceding query, we used the SELECT EXISTS statement with the subquery. In the INNER SELECT statement, we retrieve all records from the USA_PROGRAMMING_CLASS table and grouped them on the basis of the WEB_SITES_NAME column.

And with having a function MAX function on the STUDENT_ID column. It will also check along with the STUDENT_ID column value should be greater than 5.

At the end of the subquery, we used the alias clause with AS keyword and changed the name of a query to short. The short name by using the AS keyword is EXISTS_HAVING_CLAUSE.

In this particular section, we have used and understood the MariaDB EXISTS statement with the HAVING clause in the query to find exists row in the table.

Read: MariaDB Left Join

MariaDB Check If Rows Exists Order By

In this sub-topic, we will learn how to use the MariaDB EXISTS statement with the ORDER BY clause in the query. And we will explain it with the help of an illustrated example.

In MariaDB, the ORDER BY clause is used to arrange the expression or column_name in ascending or descending order in the query for the output. We use the ASC or DESC keyword in the query.

Normally, the programmers don’t use the ASC keyword with the expression because the MariaDB automatically arranges it in ascending order.

Now, let’s have a look at the MariaDB EXISTS statement with the ORDER BY clause by the following query:

EXAMPLE:

SELECT EXISTS ( SELECT * FROM USA_PROGRAMMING_CLASS
ORDER BY STUDENT_ID DESC) AS EXISTS_ORDER_BY;

• In the preceding query, we used the SELECT EXISTS statement on the subquery. In the INNER SELECT statement, we retrieve all records from the USA_PROGRAMMING_CLASS table.
• And arrange the STUDENT_ID column in descending order by using the ORDER BY clause with the DESC keyword.
• This inner query will get executed which means the SELECT EXISTS will also get executed.
• So, in the output, it will return 1 in the form of a TRUE result because the INNER SELECT statement was executed properly.

In this section, we have understood how to use the MariaDB EXISTS statement with the ORDER BY clause in the query. The main purpose of this is to find and check if rows exists in the table.

Read: MariaDB Union Operator

MariaDB Check If Rows Exists Json

Here we will understand how to use the MariaDB EXISTS statement with the JSON data type in the query. And it will be explained with the help of an illustrated example.

MariaDB’s JSON data type is a replacement for LONGTEXT, which was designed to work with MySQL’s JSON data type. Because it violates the SQL standard, MariaDB supports the JSON data format as a LONGTEXT instead, and MariaDB’s benchmarks show that efficiency is at least comparable.

Here is an illustrated example of the MariaDB EXISTS statement with the JSON data type in the below following query:

EXAMPLE:

SELECT EXISTS (SELECT * FROM JSON_DEMO
WHERE USER_NAME='Jack_k') AS EXIST_JSON_DATATYPE;

• In the above query, we have used the SELECT EXISTS statement on the subquery. In the INNER SELECT statement, we retrieve all records from the JSON_DEMO table based on the WHERE condition.
• In the WHERE condition, the USER_NAME column carries the name of the JACK_K in the column then the WHERE condition is TRUE.
• If the WHERE condition is TRUE then the outer query of the SELECT EXISTS statement will return as 1 in the form of a TRUE result.
• But if the WHERE condition is FALSE then obviously the SELECT EXISTS will also return FALSE in the form of 0 as the output result.
• At the end of the query, we have used the alias clause with AS keyword to shorter the output column name as EXIST_JSON_DATATYPE for the JSON_DEMO table.

As we have understood how to use the MariaDB EXISTS statement on the JSON data type and check if rows exist in the table.

Read: MariaDB Join with Examples

MariaDB Check If Rows Exists Multiple Columns

Here we will use the MariaDB SELECT EXISTS statement on the multiple columns of the table in the query. And let’s use an illustrated example to explain it properly.

As the sub-topic of multiple columns refers to more than one column in the table. Here’s an example is given below:

EXAMPLE:

SELECT EXISTS(SELECT STUDENT_ID,WEB_SITES_NAME FROM USA_PROGRAMMING_CLASS)
AS EXISTS_MULTIPLE_COLUMNS;

As we see in the above query, we have used the MariaDB SELECT EXISTS statement on the subquery. In the INNER SELECT statement, we retrieve records of the STUDENT_ID and WEB_SITES_NAME columns from the USA_PROGRAMMING_CLASS table.

This means that we will get the output as 1 as the SELECT EXISTS statement returns TRUE. But if the INNER SELECT statements return FALSE then as the EXISTS statement returns FALSE result we will get the output as 0.

At the end of the query, we have used the alias clause with AS keyword to shorter the query column_name and used the name as EXISTS_MULTIPLE_COLUMNS.

In this section, we have understood how to check if rows exist in the table by using the MariaDB EXISTS statement on multiple columns.

Read: MariaDB Select Into

MariaDB Check If Rows Exists Primary Key

We’ll understand and learn how to use the MariaDB EXISTS statement on the PRIMARY KEY constraint in the query. And we will explain it with the help of an illustrated example.

In MariaDB, a primary key in MariaDB can be defined as one or more fields that help to uniquely define a record in a table. A primary key column can’t contain a null value and only one column can be a primary key in the table.

Here is an example of the MariaDB EXISTS statement on the PRIMARY KEY column by the following query:

EXAMPLE:

SELECT EXISTS( SELECT * FROM USA_PROGRAMMING_CLASS
WHERE STUDENT_ID >=5) AS EXISTS_PRIMARY_KEY;

• As we see in the above query, we have used the SELECT EXISTS statement on the subquery.
• In the INNER SELECT statement, we retrieve all records from the USA_PROGRAMMINg_CLASS table with the WHERE condition.
• In the WHERE condition, it will retrieve all records from 5 in the STUDENT_ID column.
• So, if the WHERE condition is TRUE then the SELECT EXISTS statement will return the output value as 1 in the form of a TRUE value.
• And it will return a 0 value in the form of a FALSE result. At the end of the query, we have used the alias clause with AS keyword to shorter the query name in the output and give the name as EXISTS_PRIMARY_KEY.

Here we have understood the concept of MariaDB EXISTS statement with the PRIMARY KEY constraint and to check it if rows exists in the table.

Read: MariaDB DATEDIFF Function

MariaDB Check If Rows Exists Temporary Table

Here we will use the MariaDB SELECT EXISTS statement on the temporary table and which is explained with the help of an illustrated example.

In MariaDB, the main use of the TEMPORARY TABLE is that in some operations we can get benefits due to disposable data. And it also doesn’t appear in the system in old fashion way. If we use the SHOW TABLES statement, it will not reveal a single list contained in the temporary table.

First, we need to create a temporary table called USA_CLASS from the USA_PROGRAMMING_CLASS table by the following query:

CREATE TEMPORARY TABLE USA_CLASS(
STUDENT INT AUTO_INCREMENT PRIMARY KEY,
WEB_SITES_NAME VARCHAR(40),
TOTAL_STUDENT INT);

insert into USA_CLASS (WEB_SITES_NAME, TOTAL_STUDENT ) 
values ('google.co.jp', 80),
 ('macromedia.com', 31),
 ( 'ucoz.ru', 99),
 ('hostgator.com', 64),
 ('bluehost.com', 11),
 ('seesaa.net', 19),
 ('boston.com', 9),
 ('constantcontact.com', 87),
 ('wp.com', 88),
 ('domainmarket.com', 4);
 
SELECT * FROM USA_CLASS; 

• In the first query, we have created a temporary table called USA_CLASS by using the CREATE TABLE statement and which will be used for the temporary session.
• In the second query, we have used the INSERT INTO statement to insert some records in the table.
• If we want to retrieve all records from the USA_CLASS table then we will use the SELECT statement.

Here is an illustrated example of the MariaDB EXISTS statement for a temporary table by the following query:

EXAMPLE:

SELECT EXISTS( SELECT * FROM USA_CLASS
WHERE STUDENT<=5) AS EXISTS_TEMP_TABLE;

As we see in the above query, we have used the SELECT EXISTS statement on the subquery. In the INNER SELECT statement, we retrieve all records from the USA_CLASS table based on the WHERE condition. In the WHERE condition, if the condition gets TRUE then we will get records till 5 from the STUDENTS column.

So, as the INNER SELECT statement gets executed then the outer query of SELECT EXISTS will also be executed. In the output, it will return 1 in the form of a TRUE result and vice-versa. In the end, we have also used the alias clause with the AS keyword to shorter the name of the output name as EXISTS_TEMP_TABLE for the result set.

In this sub-topic, we have understood how to use the MariaDB EXISTS statement on the temporary table. And to check if rows exist in the table.

Read: MariaDB Median

MariaDB Check If Rows Exists With Null

Here we will understand how to use the MariaDB EXISTS statement with the IS NULL clause in the query. And we will explain with the help of an illustrated example.

In MariaDB, the IS NULL clause is used to return an empty string/ number or contains a NULL value in the row of that column. Here is an illustrated example of the MariaDB EXISTS condition with the IS NULL clause by the following query:

EXAMPLE:

SELECT EXISTS (SELECT * FROM MIT_STUDENTS WHERE PHYSICS IS NULL) AS EXISTS_NULL;

In the preceding query, we have used the SELECT EXISTS statement with the subquery. In the INNER SELECT subquery, we retrieve all records from the MIT_STUDETNS table based on the WHERE condition. In the WHERE condition, if the PHYSICS column provides the NULL value by using the IS NULL condition.

Then the SELECT EXISTS statement will return 1 as the output value in the form of the TRUE result set. At the end of the above query, we have used the alias clause with AS keyword to shorter the query name as EXISTS_NULL in the output.

In this sub-topic, we have understood the concept of the MariaDB EXISTS statement with the IS NULL condition in the query. The main purpose of the MariaDB EXISTS statement with the IS NULL condition is to find if rows exist in the table or not.

Also, take a look at some more MariaDB tutorials.

• MariaDB Add Column With Default Value
• MariaDB Delete From Statement
• MariaDB Difference Between Two Dates
• MariaDB Alter Table Add Index
• MariaDB Check Empty String
• MariaDB Check String Length
• MariaDB Unique Key [Useful Guide]
• MariaDB Date_Format + Examples
• MariaDB ENUM – Helpful Guide

So, in this MariaDB tutorial, we have discussed how to use the MariaDB check if rows exists statement and discussed several examples related to it. There are lists of the topic that comes under discussion:

• MariaDB Check If Rows Exists
• MariaDB Check If Rows Exists By Name
• MariaDB Check If Rows Exists Count
• MariaDB Check If Rows Exists Distinct
• MariaDB Check If Rows Exists Group By
• MariaDB Check If Rows Exist Having
• MariaDB Check If Rows Exists Order By
• MariaDB Check If Rows Exists Json
• MariaDB Check If Rows Exists Multiple Columns
• MariaDB Check If Rows Exists Primary Key
• MariaDB Check If Rows Exists Temporary Table
• MariaDB Check If Rows Exists With Null