Posts about SQL
SQL wildcard
May 16, 2021 08:00 0 Comment SQL
SQL wildcard, SQL wildcard, Grammar, Example, SQL wildcard, We've already, discussed SQL's LIKE, operator, which uses wildcards to compare two similar values., SQL supports the following two wildc
SQL uses sequences
May 16, 2021 08:00 0 Comment SQL
SQL uses sequences, SQL uses sequences, Use AUTO_INCREMENT column, Example, Gets AUTO_INCREMENT value, Perl example, PHP example, Number the existing sequence, A sequence from a specific value, SQL uses sequences, A sequence is an ordered set of integers produced as needed: 1, 2, 3 ..., Sequences are often used in databases because many appli
SQL transactions
May 16, 2021 08:00 0 Comment SQL
SQL transactions, SQL transactions, The property of the transaction, Transaction control, COMMIT command, Example, ROLLBACK command, Example:, SAVEPOINT command, Example, RELEASE SAVEPOINT command, SET TRANSACTION command, SQL transactions, A transaction is a sequence of tasks performed in a logical order on a database, neither manually by the user nor automatically by s
SQL injection
May 16, 2021 08:00 0 Comment SQL
SQL injection, SQL injection, Block SQL injection, LIKE dilemma, SQL injection, If you take user input from a Web page and insert it into a SQL database, you are probably already, exposed to a security risk, called
SQL uses views
May 16, 2021 08:00 0 Comment SQL
SQL uses views, SQL uses views, Create a view, SQL CREATE VIEW example, WITH CHECK OPTION, Update the view, Insert a new row into the view, Delete the rows in the view, Delete the view, Chapter test, SQL uses views, A view is nothing more than a SQL statement stored in a database with a name, or an component of a data table that exists in the form
SQL handles duplicate data
May 16, 2021 08:00 0 Comment SQL
SQL handles duplicate data, SQL handles duplicate data, Grammar:, Example:, SQL handles duplicate data, Sometimes, the same records exist in the data table., When obtaining records in a table, it is clearly more meaningful to
SQL TRUNCATE TABLE command
May 16, 2021 08:00 0 Comment SQL
SQL TRUNCATE TABLE command, SQL TRUNCATE TABLE command, Grammar:, Example:, SQL TRUNCATE TABLE command, The SQL, TRUNCATE TABLE command, is used to delete all data from an existing data table., You can also use the DROP TABLE
SQL sub-query
May 16, 2021 08:00 0 Comment SQL
SQL sub-query, SQL sub-query, Sub-query in select statement, Example:, Sub-queries in INSERT statements:, Example:, Sub-queries in UPDATE statements:, Example:, Sub-queries in DELETE statements:, Example:, Chapter test, SQL sub-query, Sub Query, or Inner Query, also known as Nested Query, is a query nested in the WHERE clause of other SQL queries., Sub-queries are use
SQL MS Access, MySQL, and SQL Server data types
May 16, 2021 09:00 0 Comment SQL
SQL is used for various database data types - The type and scope of data used by Microsoft Access, MySQL, and SQL Server., SQL is used for various database data types, Microsoft Access data type, MySQL data type, SQL Server data type, SQL is, used for various database data types, The type and scope of data used by Microsoft Access, MySQL, and SQL Server., Microsoft Access data type,
SQL function
May 16, 2021 09:00 0 Comment SQL
SQL function - SQL has many built-in functions that can be used for counting and calculating., SQL function, SQL Aggregate function, SQL Scalar function, Chapter test, SQL, function, SQL has many built-in functions that can be used for counting and calculating., SQL Aggregate function, The SQL Aggregate function calc
SQL MAX() function
May 16, 2021 09:00 0 Comment SQL
SQL MAX() function, SQL MAX() function, Demonstrate the database, SQL MAX() instance, Instance, SQL, MAX(), function, MAX() function, The MAX() function returns the maximum value of the selected column., SQL MAX() syntax, SELECT MAX(column_name),
SQL MIN() function
May 16, 2021 09:00 0 Comment SQL
SQL MIN() Function, SQL MIN() Function, Demonstrate the database, SQL MIN() instance, Instance, Chapter test, SQL, MIN(), Function, MIN() function, The MIN() function returns the minimum value of the selected column., SQL MIN() syntax, SELECT MIN(column_name),
SQL COUNT() function
May 16, 2021 09:00 0 Comment SQL
SQL COUNT() function, Demonstrate the database, SQL COUNT (column_name) instance, Instance, AN instance of SQL COUNT, Instance, SQL COUNT (DISTINCT column_name) instance, Instance, The COUNT() function returns the number of rows that match the specified criteria., SQL COUNT (column_name) syntax, The COUNT (column_name) function r
SQL AVG() function
May 16, 2021 09:00 0 Comment SQL
SQL AVG() function, SQL AVG() function, Demonstrate the database, SQL AVG() instance, Instance, Instance, SQL, AVG(), function, AVG() function, The AVG() function returns the average value of the numeric column., SQL AVG() syntax, SELECT AVG(column_name),
SQL SUM() function
May 16, 2021 09:00 0 Comment SQL
SQL SUM() function, SQL SUM() function, Demonstrate the database, SQL SUM() instance, Instance, Chapter test, SQL, SUM(), function, The SUM() function returns the sum of the numeric columns., SQL SUM() syntax, SELECT SUM(column_name), FROM table_name, WHERE co