Unquoted names or identifiers (such as database name, table name and column name) cannot contain blank and special characters, or crash with MySQL keywords (such as ORDER and DESC). (Try comparing the outputs produced by ' ' and \G.) We use \G (instead of ' ') to display the results vertically. You can issue a " SHOW CREATE DATABASE databaseName" to display the full command and check these default values. The CREATE DATABASE commands uses some defaults. IMPORTANT: Use SQL DROP (and DELETE) commands with extreme care, as the deleted entities are irrecoverable. Mysql> DROP DATABASE IF EXISTS southwind Mysql> CREATE DATABASE IF NOT EXISTS southwind You could optionally apply condition " IF EXISTS" or " IF NOT EXISTS" to these commands. You can create a new database using SQL command " CREATE DATABASE databaseName" and delete a database using " DROP DATABASE databaseName". We shall begin with the first table called " products" with the following columns (having data types as indicated) and rows: Database: southwindĬreating and Deleting a Database - CREATE DATABASE and DROP DATABASE Let's call our database " southwind" (inspired from Microsoft's Northwind Trader sample database). A product sales database typically consists of many tables, e.g., products, customers, suppliers, orders, payments, employees, among others. Let us begin with a simple example - a product sales database. A " test" database is provided during installation for your testing. The databases " mysql", " information_schema" and " performance_schema" are system databases used internally by MySQL. You can use SHOW DATABASES to list all the existing databases in the server. Hence, it is best to treat identifiers as case-sensitive. The names or identifiers (database names, table names, column names, etc.) are case-sensitive in some systems, but not in other systems. For clarity, they are shown in uppercase. The SQL keywords and commands are NOT case-sensitive. A table is made up of columns (or fields) and rows ( records). Each database consists of one or more tables. SHOW WARNINGS - Show the warnings of the previous statement An Example for the Beginners (But NOT for the dummies)Ī MySQL database server contains many databases (or schemas). , columnNValue) - Insert on selected Columns VALUES ( column1Value, column2Value.) - Insert on all Columns SHOW CREATE TABLE tableName - Show the CREATE TABLE statement for this tableName - Row-Level Modify a table, e.g., ADD COLUMN and DROP COLUMNĪLTER TABLE tableName ADD columnDefinitionĪLTER TABLE tableName ADD FOREIGN KEY ( columnNmae) REFERENCES tableName ( columnNmae) ALTER TABLE tableName DROP FOREIGN KEY constraintName SHOW TABLES - Show all the tables in the default databaseĭESCRIBE|DESC tableName - Describe the details for a tableĪLTER TABLE tableName. įOREIGN KEY ( columnNmae) REFERENCES tableName ( columnNmae) SHOW CREATE DATABASE databaseName - Show the CREATE DATABASE statement - Table-LevelĬolumnName columnType columnAttribute. SELECT DATABASE() - Show the default database USE databaseName - Set the default (current) database SHOW DATABASES - Show all the databases in this server Database-LevelĭROP DATABASE databaseName - Delete the database (irrecoverable!)ĭROP DATABASE IF EXISTS databaseName - Delete if it existsĬREATE DATABASE databaseName - Create a new databaseĬREATE DATABASE IF NOT EXISTS databaseName - Create only if it does not exists Summary of MySQL Commands Used in this Tutorialįor detailed syntax, check MySQL manual "SQL Statement Syntax". If you have any problems with the registration process or your account login, please contact us.Read " How to Install MySQL and Get Started" on how to install, customize, and get started with MySQL. Registration is fast, simple and absolutely free so please, join our community today! By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. If you are looking for information about Qt related issue - register and post your question. Over 90 percent of questions asked here gets answered. Qt Centre is a community site devoted to programming in C++ using the Qt framework. Select the forum that you want to visit from the selection below. Check if a table exists in a mysql databaseīefore you can post: click the register link above to proceed.
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