Wednesday , 29 September 2021
Stackode
Home > Tag Archives: MySql

Tag Archives: MySql

Laravel Syntax error or access violation: 1071

laravel-key-too-long

Trying to migrate in Laravel. When run “$ php artisan migrate” get this error : [Illuminate\Database\QueryException] SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes or Doctrine\DBAL\Driver\PDOException::("SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes or PDOException::("SQLSTATE[42000]: Syntax error or access violation: ...

Read More »

How to delete index in MySql

How to delete index in MySql, first you need to know the exact name of the INDEX (Unique key in this case) to delete or update it. INDEX names are usually same as column names. In case of more than one INDEX applied on a column, MySQL automatically suffixes numbering to the column names to create unique INDEX names. For ...

Read More »

Overview – SQL

Overview – SQL tutorial gives unique learning on Structured Query Language and it helps to make practice on SQL commands which provides immediate results. SQL is a language of database, it includes database creation, deletion, fetching rows and modifying rows etc. SQL is an ANSI (American National Standards Institute) standard but there are many different versions of the SQL language. ...

Read More »

Update Query – SQL

Update Query – SQL is used to modify the existing records in a table. You can use WHERE clause with UPDATE query to update selected rows otherwise all the rows would be affected. Syntax: The basic syntax of UPDATE query with WHERE clause is as follows: UPDATE table_name SET column1 = value1, column2 = value2...., columnN = valueN WHERE [condition]; ...

Read More »

Using Views – SQL

Using Views – SQL –  is nothing more than a SQL statement that is stored in the database with an associated name. A view is actually a composition of a table in the form of a predefined SQL query. A view can contain all rows of a table or select rows from a table. A view can be created from ...

Read More »

SUM Function SQL

SUM Function SQL is used to find out the sum of a field in various records. To understand SUM function, consider an employee_tbl table, which is having the following records: SQL> SELECT * FROM employee_tbl; +------+------+------------+--------------------+ | id | name | work_date | daily_typing_pages | +------+------+------------+--------------------+ | 1 | John | 2007-01-24 | 250 | | 2 | Ram | ...

Read More »

RDBMS Concepts – SQL

What is RDBMS? RDBMS stands for Relational Database Management System. RDBMS is the basis for SQL, and for all modern database systems like MS SQL Server, IBM DB2, Oracle, MySQL, and Microsoft Access. A Relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd. What is ...

Read More »

Delete Query – SQL

Delete Query – SQL is used to delete the existing records from a table. You can use WHERE clause with DELETE query to delete selected rows, otherwise all the records would be deleted. Syntax: The basic syntax of DELETE query with WHERE clause is as follows: DELETE FROM table_name WHERE [condition]; You can combine N number of conditions using AND ...

Read More »

Having Clause – SQL

Having Clause – SQL enables you to specify conditions that filter which group results appear in the final results. The WHERE clause places conditions on the selected columns, whereas the HAVING clause places conditions on groups created by the GROUP BY clause. Syntax: The following is the position of the HAVING clause in a query: SELECT FROM WHERE GROUP BY ...

Read More »

SQRT Function SQL

SQRT Function SQL is used to find out the square root of any number. You can Use SELECT statement to find out square root of any number as follows: SQL> select SQRT(16); +----------+ | SQRT(16) | +----------+ | 4.000000 | +----------+ 1 row in set (0.00 sec) You are seeing float value here because internally SQL will manipulate square root ...

Read More »