SELECT in MySQL doesn't return a row when a field is NULL and a filter LIKE '%'

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I have a table with a field: - field1 (Varchar(10)) Default NULL;

When I run this SQL:

SELECT * FROM table WHERE field1 LIKE '%';

That query does not return rows where Field1 IS NULL;

Why NULL it is not considered as any value?

What solution do I have? I don't know the default value of the fields in a table to make a query.

NULL is an unknown value or missing value. So use COALESCE function to make the null value to a non-null value.

Query

select * from `table`
where coalesce(`field1`, '') like '%';

MySQL 8.0 Reference Manual :: 1.8.2.1 SELECT INTO , 2.1 SELECT INTO TABLE Differences. MySQL Server doesn't support the SELECT INTO TABLE Sybase SQL extension. Instead, MySQL Server supports the  I am trying to create a php script that selects one row from my table by using the WHERE clause. The problem is the mysql query returns no rows. I know the variable is correct (its user submitted).

SELECT *FROM table_name where column_name is null

try this code.

13.2.6.1 INSERT SELECT Statement, However, you cannot insert into a table and select from the same table in a subquery. When selecting from and inserting into the same table, MySQL creates an  Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. Provide details and share your research! But avoid … Asking for help, clarification, or responding to other answers. Making statements based on opinion; back them up with references or personal experience. To learn more, see our tips on writing great

When you type LIKE '%', that means something like «any string with any character», and NULL is not a string.

If you want rows that only contains null, you must write :

SELECT * FROM table WHERE field1 IS NULL;

But if you want all rows, you can remove the WHERE part, and write this:

SELECT * FROM table

13.1.20.4 CREATE TABLE SELECT Statement, The SELECT part of the statement cannot assign values to generated columns in the destination table. For CREATE TABLE SELECT , the destination table does​  The statement ‘select 1’ from any table name means that it returns only 1. For example, If any table has 4 records then it will return 1 four times. Let us see an example.

Can't select from mysql table, I want to select all columns from 'catalog' table. Used this code, but it doesn't work​. $link = mysqli_connect('localhost'  MySQL Not equal is used to return a set of rows (from a table) after making sure that two expressions placed on either side of the NOT EQUAL TO (<>) operator are not equal. Syntax: <>, != MySQL Version: 5.6. Example: MySQL not equal to (<>) operator

MySQL SELECT, MySQL doesn't require this. However, placing the FROM keyword on a new line will make the query easier to read and simpler to maintain. When evaluating the  The CASE statement goes through conditions and return 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 will return the value in the ELSE clause. If there is no ELSE part and no conditions are true, it returns NULL.

How to Use The MySQL REPLACE Statement to Insert or Update, If the table does not have one of these indexes, the REPLACE works like an INSERT Using MySQL REPLACE to insert data from a SELECT statement. The SELECT statement allows you to read data from one or more tables. To write a SELECT statement in MySQL, you follow this syntax: SELECT select_list FROM table_name; Let’s look at each part of the statement.

Comments
  • SELECT * FROM table should do. LIKE % means you are getting all rows except nuLL
  • I have a form with a filter input name, and I need my query to work when that field is left empty: SELECT * FROM table WHERE field1 LIKE '%$_POST["name"]';
  • when that field is left empty by user input, You should simply ignore that condition in your where clause. This will make your query more efficient.