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Found 6705 Articles for Database

740 Views
To get result from multiple select statements, use UNION ALL. Following is the syntax −select yourValue1 AS anyColumnName UNION ALL select yourValue2 AS yourColumnName . . . . NLet us implement the above syntax in order to return enumeration of numbers in different rows −mysql> select 100 AS Number UNION ALL select 1000 AS Number UNION ALL select 10000 AS Number UNION ALL select 100000 AS Number UNION ALL select 1000000 AS Number UNION ALL select 10000000 AS Number UNION ALL select 100000000 AS Number UNION ALL select 1000000000 AS Number;This will produce the following output -+------------+ | Number | +------------+ | 100 | | 1000 | | 10000 | | 100000 | | 1000000 | | 10000000 | | 100000000 | | 1000000000 | +------------+ 8 rows in set (0.00 sec)

8K+ Views
To select last two rows, use ORDER BY DESC LIMIT 2.Let us first create a table −mysql> create table DemoTable763 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, FirstName varchar(100) ); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command −mysql> insert into DemoTable763(FirstName) values('John'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable763(FirstName) values('Sam'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable763(FirstName) values('Carol'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable763(FirstName) values('David'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable763(FirstName) ... Read More

709 Views
For this, you can use LIKE operator with OR condition.Let us first create a table −mysql> create table DemoTable762 (Title text); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command −mysql> insert into DemoTable762 values('Introduction to Java'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable762 values('MySQL is a RDBMS'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable762 values('Data Structure and Algorithm in Java'); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable762 values('Data Structure and Algorithm in C and C++'); Query OK, 1 row affected (0.18 ... Read More

432 Views
The strings (column values) begun with a character and rest of the string has numbers. We want the sum of these numbers −J230 A130s C13For this, use SUBSTRING() function along with SUM().Let us first create a table −mysql> create table DemoTable761 (Price varchar(100)); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable761 values('J230'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable761 values('A130'); Query OK, 1 row affected (0.70 sec) mysql> insert into DemoTable761 values('C13'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable761 values('D456'); Query ... Read More

206 Views
Let us first create a table −mysql> create table DemoTable760 ( ClientId int, ClientId2 int ); Query OK, 0 rows affected (0.79 sec)Insert some records in the table using insert command −mysql> insert into DemoTable760 values(100, 200); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable760 values(100, 200); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable760 values(300, 400); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable760 values(300, 400); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable760 values(100, 200); Query OK, 1 row affected (0.23 sec) mysql> insert ... Read More

402 Views
To set NULL values, set the type as NULL as in the below syntax −yourColumnName dataType NULL;Let us first create a table −mysql> create table DemoTable759 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, FirstName varchar(100) NULL ); Query OK, 0 rows affected (0.72 sec)Insert some records in the table using insert command −mysql> insert into DemoTable759(FirstName) values('John'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable759(FirstName) values(NULL); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable759(FirstName) values('Carol'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable759(FirstName) values(NULL); Query OK, 1 row ... Read More

1K+ Views
To set the default value, use the DEFAULT keyword.Let us first create a table −mysql> create table DemoTable758 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, FirstName varchar(100) ); Query OK, 0 rows affected (0.66 sec)Following is the query to set default value for a column −mysql> alter table DemoTable758 add column Colors ENUM('RED', 'GREEN', 'BLUE', 'ORANGE', 'YELLOW') DEFAULT 'YELLOW'; Query OK, 0 rows affected (0.44 sec) Records: 0 Duplicates: 0 Warnings: 0Let us check the description of table once again −mysql> desc DemoTable758;This will produce the following output -+-----------+----------------------------------------------+------+-----+---------+----------------+ | Field | Type ... Read More

556 Views
Let’s say you have a VARCHAR column in a table with values are strings and the numbers are on the right side. For example −John1023 Carol9871 David9098Now, consider you want to order by on the basis of these right-side numbers in the entire column. For this, use ORDER BY RIGHT.Let us first create a table −mysql> create table DemoTable757 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, ClientId varchar(100) ); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert command −mysql> insert into DemoTable757(ClientId) values('John1023'); Query OK, 1 row ... Read More

1K+ Views
Let us first create a table −mysql> create table DemoTable756 ( Value1 int, Value2 int, Value3 int ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable756 values(10, 20, 14); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable756 values(20, 34, 17); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable756 values(200, 134, 789); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable756 values(139, 98, 99); Query OK, 1 row affected (0.17 sec)Display all records from the table using select statement ... Read More

387 Views
For this, use alias on HAVING clause.Let us first create a table −mysql> create table DemoTable755 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Score1 int, Score2 int ); Query OK, 0 rows affected (0.62 sec)Insert some records in the table using insert command −mysql> insert into DemoTable755(Score1, Score2) values(30, 23); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable755(Score1, Score2) values(50, 60); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable755(Score1, Score2) values(89, 90); Query OK, 1 row affected (0.29 sec) mysql> insert into DemoTable755(Score1, Score2) values(99, 99); Query OK, 1 row ... Read More