What is basic SELECT statement?

SELECT Statement A SELECT statement retrieves data from the database. With SELECT statement PROJECTION, SELECTION and JOIN can be performed on database tables. As data in relational database is stored in TABLES. TABLE has ROW and COLUMN structure. With SELECT statement all rows and all columns can be retrieved, this is known as PROJECTION. But, if rows and columns are retrieved on the basis of some condition, it is known as SELECTION. And suppose if some information is needed and that is stored in two or more different tables but are related, use JOINS to retrieve it from two or more tables. In SQL, basic SELECT statements are as follows: SELECT  * FROM  [ table_name ] ; SELECT   [ column1 ] ,  [ column2 ] ,  [ column3 ] ,   .....   FROM   [ table_name ] ; SELECT and FROM are known as clauses.  SELECT clause allows to specify columns to be selected from the database table.  FROM clause allows to specify table name that has those column to be s

What are main functions of a database administrator (DBA) ?

  • Create database schema by using Data Definition Language (DDL).
  • Provide physical organization for storing data in a database.
  • Modify database schema as per the requirements.
  • Grant and authorize database access privileges to ensure data security.
  • Take timely backup for preventing data loss because of any unforeseen reasons.
  • Manage data storage memory.
  • Implement access optimization schemes.
  • Monitor automatic batch jobs and load maintenance.


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