DBA – MySQL, PostgreSQL, MongoDB, Oracle
This oracle tutorial is about using sub-queries in SQL SELECT statements in Oracle Database 11g. A subquery is a query that put inside a main query and pass the results of the query to the main query.A subquery in the FROM clause of a SELECT statement is also called an inline view. A subquery in…
I had to arrange training session on Database Management System to my colleagues which used oracle as backend. This oracle tutorial includes: Cross joins Natural joins USING clause Table alias ON clause OUTER joins Cartesian product Download: Displaying data from multiple tables
Background: One of my development project initially was on SQL Server as backend database. But consistently facing problem of ‘ODBC failed to connect’ throughout a year. The database was the SQL Server XE. Convinced to transfer my database to Oracle as it is very reliable on ODBC connection. So intended to initiate a database design migration from…
Case: Today morning on my development machine (Windows 10 ) I can’t login to the oracle schema with toad or from my application showing Oracle Error : No listener. Upon further investigation found that listener is not starting Automatically though its service configured to run automatically. Workaround: To resolve the “No Listener”, restarted workstation several times after changes…
This Oracle Tutorial: Using single-row or multiple-row functions contains the lessons mentioned below: Types of SQL Functions Single Row Functions Number Functions Character Functions Date Functions Conversion Functions General Functions Multiple Row/Aggregate Functions Restricting Group results With HAVING Clause Nesting Group Functions Download: Using single-row or multiple-row functions to customize output
This Oracle Tutorial: Retrieving data using SQL SELECT statements contains the below Topics: Limiting rows in SELECT statement Character Strings and Dates Comparison Operators Logical Operators Sorting Rows Substitution Variables Download: Retrieving data using SQL SELECT statements
I had to arrange training session over Database Management System to my colleagues which used oracle as backend. This “Oracle Tutorial: SQL SELECT Statements” is about basics of DBMS, SQL and SELECT statements. Includes: Types of SQL statement Arithmetic Operators and Precedence Null Values Column Alias Concatenation Operator/Literal Character String Duplicate Rows/DISTINCT keyword Download: SQL Select…