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Found 6705 Articles for Database

622 Views
To understand the MySQL select statement DISTINCT for multiple columns, let us see an example and create a table. The query to create a table is as followsmysql> create table selectDistinctDemo -> ( -> InstructorId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> StudentId int, -> TechnicalSubject varchar(100) -> ); Query OK, 0 rows affected (0.50 sec)Insert some records in the table using insert command. The query is as followsmysql> insert into selectDistinctDemo(StudentId, TechnicalSubject) values(121, 'Java'); Query OK, 1 row affected (0.15 sec) mysql> insert into selectDistinctDemo(StudentId, TechnicalSubject) values(121, 'MongoDB'); Query OK, 1 row affected (0.16 ... Read More

579 Views
For this, you need to use an INSERT SELECT statement. The syntax is as followsINSERT INTO yourDatabaseName1.yourTableName1(yourColumnName1, yourColumnName2, ....N) SELECT yourColumnName1, yourColumnName2, ....N FROM yourdatabaseName2.yourTableName2;Here, I am using the following two databasessampletestLet us create the first table in the “test” databasemysql> use test; Database changed mysql> create table send -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> Name varchar(20) -> ); Query OK, 0 rows affected (1.19 sec)Insert some records in the first table using insert command. The query is as followsmysql> insert into send(Name) values('John'); Query OK, 1 row affected ... Read More

2K+ Views
Let us first create a table. The query to create a table is as followsmysql> create table FirstAndLastDataDemo -> ( -> EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> EmployeeName varchar(20), -> EmployeeAge int -> ); Query OK, 0 rows affected (0.59 sec)Insert some records in the table using insert command. The query is as followsmysql> insert into FirstAndLastDataDemo(EmployeeName, EmployeeAge) values('John', 23); Query OK, 1 row affected (0.15 sec) mysql> insert into FirstAndLastDataDemo(EmployeeName, EmployeeAge) values('Bob', 13); Query OK, 1 row affected (0.11 sec) mysql> insert into FirstAndLastDataDemo(EmployeeName, EmployeeAge) values('Larry', 24); Query OK, 1 row affected ... Read More

921 Views
You can use INFORMATION_SCHEMA.COLUMNS table to display MySQL table name with columns. The syntax is as follows −SELECT DISTINCT TABLE_NAME, Column_Name FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = 'yourDatabaseName';Here, we have a database with the name ‘sample’ with tables. The query is as follows to display table name along with column name −mysql> SELECT DISTINCT TABLE_NAME, Column_Name -> FROM INFORMATION_SCHEMA.COLUMNS -> WHERE TABLE_SCHEMA = 'sample';Output+--------------------------------+-------------------------------+ | TABLE_NAME | COLUMN_NAME | +--------------------------------+-------------------------------+ | aggregatefunctiondemo | UserId ... Read More

2K+ Views
Achieve this with the help of where clause.The syntax is as followsSELECT yourColumnName1, yourColumnName2, ...N FROM yourTableName WHERE ( SELECT COUNT(*) FROM yourTableName )=2;To understand the concept, let us create a table. The query to create a table is as followsmysql> create table CountWithSubqueryDemo - > ( - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > EmployeeName varchar(20) - > ); Query OK, 0 rows affected (2.09 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into CountWithSubqueryDemo(EmployeeName) values('John'); Query OK, 1 row affected (0.54 sec) mysql> ... Read More

1K+ Views
You need to use substring_index() function from MySQL to select text.The syntax is as followsSELECT substring_index(yourColumnName, '/', -1) AS anyAliasName FROM yourTableName;To understand the above concept, let us create a table. The query to create a table is as followsmysql> create table selectTextAfterLastSlashDemo - > ( - > UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > UserPathDirectory varchar(200) - > ); Query OK, 0 rows affected (0.54 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into selectTextAfterLastSlashDemo(UserPathDirectory) values('C:/MyFolder1/MyEntityFramework'); Query OK, 1 ... Read More

1K+ Views
The best way to change the date format in MySQL SELECT is as followsSELECT DATE_FORMAT(yourColumnName, "%d/%m/%Y %H:%i") AS anyAliasName FROM yourTableName WHERE yourCondition;To understand the above concept, let us create a table. The query to create a table is as followsmysql> create table bestDateFormatDemo - > ( - > Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > ArrivalDateTime datetime - > ); Query OK, 0 rows affected (0.64 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into bestDateFormatDemo(ArrivalDateTime) values(now()); Query OK, ... Read More

143 Views
Yes, you can get expanded out in MySQL using the /G, instead of semicolon(;). The syntax is as followsSELECT *FROM yourTableName\GLet us first create a table as an examplemysql> create table expandedOutputDemo - > ( - > EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY, - > EmployeeName varchar(20), - > EmployeeAge int - > ); Query OK, 0 rows affected (0.66 sec)Insert some records in the table using insert command.The query is as followsmysql> insert into expandedOutputDemo(EmployeeName, EmployeeAge) values('Larry', 27); Query OK, 1 row affected (0.16 sec) mysql> insert into expandedOutputDemo(EmployeeName, EmployeeAge) values('Mike', 29); Query ... Read More

252 Views
Get the create and update tables exact date using the create_time or update_time in MySQL.At first, use the SHOW command. The syntax is as followsSHOW TABLE STATUS;We are considering our database ‘test3’, which is already having some tablesmysql> use test3; Database changedNow use the following query to display all the tables in the database test3mysql> show tables;The following is the output+-------------------------+ | Tables_in_test3 | +-------------------------+ | add6hour | | deletedemo | | differentdatetime | | fieldlessthan5chars | | ... Read More

657 Views
The syntax is as follows to rename Root @localhostUPDATE MySQL.user SET user = ‘yourNewRootName’ WHERE user = 'root';To understand the above concept, let us check all the user names and host. The query is as followsmysql> select user, host from MySQL.user;The following is the output+------------------+-----------+ | user | host | +------------------+-----------+ | Bob | % | | Manish | % | | User2 | % ... Read More