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Articles by Chandu yadav
Page 75 of 81
How to Reset MySQL AutoIncrement using a MAX value from another table?
You can use prepare statement to Reset MySQL AutoIncrement using a MAX value from another table.The following is the syntax −set @anyVariableName1=(select MAX(yourColumnName) from yourTableName1); SET @anyVariableName2 = CONCAT('ALTER TABLE yourTableName2 AUTO_INCREMENT=', @anyVariableName1); PREPARE yourStatementName FROM @anyVariableName2; execute yourStatementName;The above syntax will reset MySQL auto_increment using a maximum value from another table. To understand the above syntax, let us create two tables. The first table will contain the records and the second table will use the maximum value from the first table and use for an auto_increment property.The query to create a table is as follows −mysql> create table FirstTableMaxValue ...
Read MoreCan MySQL automatically store timestamp in a row?
Yes, you can achieve this in the following two ways.First Approach At the time of creation of a table.Second Approach At the time of writing query.The syntax is as follows.CREATE TABLE yourTableName ( yourDateTimeColumnName datetime default current_timestamp );You can use alter command.The syntax is as follows.ALTER TABLE yourTableName ADD yourColumnName datetime DEFAULT CURRENT_TIMESTAMP;Implement both the syntaxes now.The first approach is as follows.mysql> create table CurrentTimeStampDemo -> ( -> CreationDate datetime default current_timestamp -> ); Query OK, 0 rows affected (0.61 sec)If you do not pass any parameter for the column ‘CreationDate’, MySQL by default stores the current timestamp.Insert record in ...
Read MoreHow to delete last record (on condition) from a table in MySQL?
To delete last record (on condition) from a table, you need to use ORDER BY DESC with LIMIT 1. The syntax is as follows:DELETE FROM yourTableName WHERE yourColumnName1=yourValue ORDER BY yourColumnName2 DESC LIMIT 1;The above syntax will delete last record (on condition) from a table. It sorts the column in descending order and choose the first element to delete.To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table UserLoginTable -> ( -> Id int NOT NULL AUTO_INCREMENT, -> UserId int, -> UserLoginDateTime datetime, -> PRIMARY ...
Read MoreMySQL increment a database field by 1?
You can increment a database using update command. The syntax is as follows −UPDATE yourTableName set yourColumnName=yourColumnName+1 where condition;To understand the above syntax, let us first create a table. The query to create a table is as follows −mysql> create table IncrementBy1 -> ( -> Id int, -> Name varchar(100), -> CounterLogin int -> ); Query OK, 0 rows affected (0.63 sec)Insert some records using insert command. The query to insert records in the table is as follows −mysql> insert into IncrementBy1 values(100, 'John', 30); Query OK, 1 row affected (0.17 sec) mysql> insert ...
Read MoreChange MySQL default character set to UTF-8 in my.cnf?
To change MySQL default character set to UTF-8 in my.cnf, firstly reach the location of my.cnf file.The following is the screenshot of “my.cnf” file. Firstly, open the C: directory and the “Program Data” folder −Now, click on “MySQL” folder −Now, click the MySQL Server 8.0 folder and open it −After opening MySQL Server 8.0, you will get “my.cnf” file location.After opening my.cnf file, you will get the character-set. Open the file and the following contens are visible −Now you can change the character-set to utf8.
Read MoreUpdate MySQL date and increment by one Year?
You can use in-built function date_add() from MySQL. The syntax is as follows −UPDATE yourTableName SET yourDateColumnName=DATE_ADD(yourDateColumnName, interval 1 year);To understand the above syntax, let us first create a table. The query to create a table is as follows −mysql> create table UpdateDate -> ( -> Id int, -> DueDate datetime -> ); Query OK, 0 rows affected (0.76 sec)Insert some records in the table using insert command. The query to insert record is as follows −mysql> insert into UpdateDate values(1001, '2012-5-21'); Query OK, 1 row affected (0.17 ...
Read MoreTruncate with condition in MySQL?
In MySQL, there is no way to truncate with condition. You cannot use truncate statement with where clause.If you want the condition, use delete command −DELETE FROM yourTableName WHERE youCondition;The above syntax is fine but if you want a faster solution, then DELETE is not good in comparison to Truncate. The advantage with truncate is that it does not write to the logs.Let us create a table. The query to create a table is as follows −mysql> create table DeleteDemo -> ( -> Id int, -> Name varchar(100) ...
Read MoreMySQL create user if it does not exist?
You can create user if it does not exist with the help of “create user” command. The command will work on MySQL version 5.7.6 and above. The syntax is as follows −mysql> CREATE USER IF NOT EXISTS 'yourUserName'@'localhost' IDENTIFIED BY 'yourPassword';Apply the above syntax to create a user if it does not exist. The query is as follows −mysql> CREATE USER IF NOT EXISTS 'Smith'@'localhost' IDENTIFIED BY 'Smith123456'; Query OK, 0 rows affected (0.29 sec)To check the new user is created or not, use the below query −mysql> SELECT User FROM mysql.user;The following is the output −+------------------+ | User ...
Read MoreHow to find MySQL my.cnf on my windows computer?
To find my.cnf on Windows system, first open the command prompt with the help of shortcut key Windows + R (run). The snapshot is as follows −Type “services.msc” on command prompt and press ENTER as shown in the following screenshot −Now, a new wizard will open. The snapshot is as follows −Now, search for MySQL. The snapshot is as follows −Right click on “MySQL80” and select “Properties” as in the following screenshot −As you can see in the above screenshot, “Path to executable” tells about the location of my.cnf on Windows.
Read More8085 Block movement without overlap
In this program, we will see how to move blocks of data from one place to another.Problem StatementWrite 8085 Assembly language program to move a data block. The blocks are assumed to be non-overlapping. The block size is given, the block is starting from X and we have to move it to the location Y.DiscussionThe non-overlapping block movement is relatively an easy task. Here the block is starting at position X, we have to move it to position Y. The location Y is far away from X. So Y > X + block size.In this program, the data are stored ...
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