For this, use SUBSTRING_INDEX(). Let us first create a table −mysql> create table DemoTable2040    -> (    -> StudentCode varchar(20)    -> ); Query OK, 0 rows affected (0.85 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2040 values('John-232'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable2040 values('Carol-901'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable2040 values('David-987'); Query OK, 1 row affected (0.21 sec)Display all records from the table using select statement −mysql> select *from DemoTable2040;This will produce the following output −+-------------+ | StudentCode | +-------------+ | ... Read More

To display a list of records in a specific order, you need to set conditions and use ORDER BY. For this, use ORDER BY CASE statement. Let us first create a table −mysql> create table DemoTable2039    -> (    -> Name varchar(20)    -> ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2039 values('John Doe'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable2039 values('John Smith'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable2039 values('Chris Brown'); Query OK, 1 row affected ... Read More

To return TRUE for positive values and FALSE for negative, use MySQL IF(). Let us first create a table −mysql> create table DemoTable2038    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Value int    -> ); Query OK, 0 rows affected (0.87 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2038(Value) values(57); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable2038(Value) values(-100);; Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable2038(Value) values(-78); Query OK, 1 row affected (0.42 sec) mysql> insert into DemoTable2038(Value) ... Read More

Let us first create a table. Here, we have set the status using ENUM −mysql> create table DemoTable2037    -> (    -> StudentId int,    -> status enum('Active', 'Inactive')    -> ); Query OK, 0 rows affected (0.51 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2037 values(99, 'Active'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable2037 values(99, 'Inactive'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable2037 values(100, 'Inactive'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable2037 values(99, 'Active'); Query OK, 1 row ... Read More

For this, use the concept of LEFT() function. Let us first create a table −mysql> create table DemoTable2036    -> (    -> FirstLetter varchar(20),    -> Title varchar(20)    -> ); Query OK, 0 rows affected (1.01 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2036(Title) values('Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable2036(Title) values('John'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable2036(Title) values('Adam'); Query OK, 1 row affected (0.15 sec)Display all records from the table using select statement −mysql> select *from DemoTable2036;This will produce the ... Read More

Let us create a custom function to validate date in MySQL −mysql> set global log_bin_trust_function_creators=1; Query OK, 0 rows affected (0.03 sec) mysql> delimiter // mysql> create function isValidDate(actualDate varchar(255)) returns int    -> begin    -> declare flag int;    -> if (select length(date(actualDate)) IS NOT NULL ) then    -> set flag = 1;    -> else    -> set flag = 0;    -> end if;    -> return flag;    -> end    -> // Query OK, 0 rows affected (0.11 sec) mysql> delimiter ;Case 1 −When parameter is null value i.e. the date to be ... Read More

Set the column as BOOLEAN to display 0 and 1 values. Let us create a table −mysql> create table DemoTable2035    -> (    -> Id int NOT NULL AUTO_INCREMENT,    -> Name varchar(20),    -> isMarried boolean,    -> PRIMARY KEY(Id)    -> ); Query OK, 0 rows affected (0.72 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2035(Name, isMarried) values('Chris', true); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable2035(Name, isMarried) values('David', false); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable2035(Name, isMarried) values('Bob', true); Query OK, 1 ... Read More

To declare a variable, use DECLARE in a MySQL stored procedure. Let us first create a table −mysql> create table DemoTable2034    -> (    -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> StudentName varchar(20),    -> StudentAge int    -> ); Query OK, 0 rows affected (0.49 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2034(StudentName, StudentAge) values('Chris', 23); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable2034(StudentName, StudentAge) values('David', 21); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable2034(StudentName, StudentAge) values('Robert', 25); Query OK, 1 row ... Read More

For dynamic SQL query in a stored procedure, use the concept of PREPARE STATEMENT. Let us first create a table −mysql> create table DemoTable2033    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Name varchar(20)    -> ); Query OK, 0 rows affected (1.61 sec)Insert some records in the table using insert command −mysql> insert into DemoTable2033(Name) values('Chris'); Query OK, 1 row affected (0.85 sec) mysql> insert into DemoTable2033(Name) values('Bob'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable2033(Name) values('David'); Query OK, 1 row affected (0.24 sec) mysql> insert into ... Read More

To detect the existence of a table, use the concept of INFORMATION_SCHEMA.TABLES. Following is the syntax −select table_name from information_schema.tables where table_schema=database() and table_name=yourTableName;To understand the above syntax, let us create a table −mysql> create table DemoTable2032    -> (    -> ClientId int,    -> ClientName varchar(20),    -> ClientAge int,    -> ClientCountryName varchar(20)    -> ); Query OK, 0 rows affected (1.07 sec)Here is the query to detect if a table exist in a database −mysql> select table_name from information_schema.tables -> where table_schema=database() -> and table_name='DemoTable2032';This will produce the following output ... Read More