Database Articles

Page 393 of 547

MySQL query to calculate the total amount from column values with Cost and Quantity?

AmitDiwan
AmitDiwan
Updated on 01-Oct-2019 1K+ Views

Let us first create a table −mysql> create table DemoTable (    Cost int,    Quantity int ); Query OK, 0 rows affected (0.80 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(65, 2); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values(290, 4); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(40, 3); Query OK, 1 row affected (0.10 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+------+----------+ | Cost | Quantity | +------+----------+ | 65 ...

Read More

MySQL query to check if a string contains a word?

AmitDiwan
AmitDiwan
Updated on 01-Oct-2019 2K+ Views

For this, you can use the LIKE operator along with CONCAT() function. Let us first create a table −mysql> create table DemoTable (    Value text ); Query OK, 0 rows affected (0.63 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('MySQL'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Is'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values('Relational'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values('Database'); Query OK, 1 row affected (0.13 sec)Display all records from the table using select statement −mysql> select ...

Read More

How to select all the records except a row with certain id from a MySQL table?

AmitDiwan
AmitDiwan
Updated on 01-Oct-2019 950 Views

To avoid displaying a certain id from a table, you need to use the operator, which is the NOT EQUAL operator. Let us first create a table −mysql> create table DemoTable7 (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    StudentName varchar(40) ); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert command −mysql> insert into DemoTable7(StudentName) values('Chris'); Query OK, 1 row affected (0.25 sec) mysql> insert into DemoTable7(StudentName) values('Robert'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable7(StudentName) values('Mike'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable7(StudentName) ...

Read More

How to update empty string to NULL in MySQL?

AmitDiwan
AmitDiwan
Updated on 01-Oct-2019 1K+ Views

For this, use LENGTH(), since if the length is 0 that would mean the string is empty. After finding, you can set it to NULL using the SET clause in the UPDATE command. Let us first create a table −mysql> create table DemoTable (    Name varchar(50) ); Query OK, 0 rows affected (0.68 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(''); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.12 sec) mysql> ...

Read More

Get the first 10 rows followed by the syntax to display remaining row records with a single MySQL query

AmitDiwan
AmitDiwan
Updated on 01-Oct-2019 214 Views

Let us first create a table −mysql> create table DemoTable (    Id int ); Query OK, 0 rows affected (0.71 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.31 sec) mysql> insert into DemoTable values(101); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable values(102); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(103); Query OK, 1 row affected (0.64 sec) mysql> insert into DemoTable values(104); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values(105); Query OK, 1 row affected ...

Read More

MySQL query to display the first alphabet from strings in a separate column

AmitDiwan
AmitDiwan
Updated on 01-Oct-2019 19K+ Views

To fetch the first alphabet from the strings, use LEFT(). This method allows you to return characters from the left of the string.Let us first see an example and create a table −mysql> create table DemoTable (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    FirstName varchar(100) ); Query OK, 0 rows affected (1.03 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(FirstName) values('John'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable(FirstName) values('Adam'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(FirstName) values('Jace'); Query OK, 1 row affected (0.16 sec) ...

Read More

MySQL query to select three highest values and sort alphabetically on the basis of corresponding column with name

AmitDiwan
AmitDiwan
Updated on 01-Oct-2019 879 Views

For this, you can use the ORDER BY clause. Let us first create a table −mysql> create table DemoTable (    Name varchar(40),    Score int ); Query OK, 0 rows affected (1.11 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris', 45); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable values('Bob', 98); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('David', 78); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values('Mike', 96); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Carol', 43); ...

Read More

Adding records with REPLACE INTO to mimic DELETE and INSERT

AmitDiwan
AmitDiwan
Updated on 01-Oct-2019 205 Views

You can use REPLACE INTO that works like DELETE + INSERT. Let us first create a table −mysql> create table DemoTable (    Id int,    FirstName varchar(50) ); Query OK, 0 rows affected (0.60 sec)Following is the query to create a unique index −mysql> alter table DemoTable add unique id_index(Id); Query OK, 0 rows affected (0.41 sec) Records: 0 Duplicates: 0 Warnings: 0Insert some records in the table using insert command. Since we have added duplicate records, the new record gets added i.e. replaced with the same Id with the previous record −mysql> replace into DemoTable values(100, 'Chris'); Query ...

Read More

A single MySQL query to find the highest and lowest among two tables?

AmitDiwan
AmitDiwan
Updated on 01-Oct-2019 232 Views

To find the highest and lowest from two tables, use MAX() and MIN(). Since the results are to be displayed from two tables, you need to use UNION. Let us first create a table −mysql> create table DemoTable1 (    UniqueId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    Score1 int ); Query OK, 0 rows affected (0.76 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1(Score1) values(56); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable1(Score1) values(76); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1(Score1) values(65); Query OK, 1 row affected ...

Read More

Can we skip column when inserting into MySQL?

AmitDiwan
AmitDiwan
Updated on 01-Oct-2019 821 Views

If your first column is AUTO_INCREMENT, then you can skip the column and place the value NULL. Let us first create a table −mysql> create table DemoTable (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    StudentFirstName varchar(100),    StudentAge int ); Query OK, 0 rows affected (0.60 sec)Insert some records in the table using insert command. Here, we have skipped the first column, since it is AUTO_INCREMENT −mysql> insert into DemoTable values(NULL, 'Robert', 21); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values(NULL, 'Sam', 22); Query OK, 1 row affected (0.18 sec) mysql> insert into ...

Read More
Showing 3921–3930 of 5,468 articles
« Prev 1 391 392 393 394 395 547 Next »
Advertisements