How to Compare Two Queries in SQL
Queries in SQL :
A query will either be an invitation for data results from your info or for action on the info, or each. a question will provide you with a solution to a straightforward question, perform calculations, mix data from totally different tables, add, change, or delete data from info.
Creating a Database :
We use CREATE DATABASE command to create a new SQL database.
Syntax -
CREATE DATABASE db_name;
Creating a Table into a created Database :
We use the CREATE TABLE command to create a new SQL database.
Syntax -
CREATE TABLE table_name (
col1 datatype,
col2 datatype,
col3 datatype,
);
Inserting the values into created Table :
We use INSERT INTO command to create a new SQL database.
Syntax -
INSERT INTO table_name
VALUES (value1, value2, value3);
Example Code to create a database and a table into it -
CREATE DATABASE myDatabase;
CREATE TABLE myTable
(
Pid int,
FName varchar(255),
LName varchar(255),
Adrs varchar(255),
District varchar(255)
);
INSERT INTO myTable (Pid, FName, LName, Adrs, District)
VALUES ('1','Krishna','Kripa','Jansa','Varanasi');
Output -
myDatabase: myTable | ||||
Pid | FName | LName | Adrs | District |
1 | Krishna | Kripa | Jansa | Varanasi |
Comparison of Queries :
For example, we've 2 similar tables in completely different databases and we wish to understand what's different. Here are the scripts that make sample databases, tables, and information.
CREATE DATABASE myDatabase1;
GO
USE myDatabase1;
GO
CREATE TABLE myTable
(
Aid int,
Atype varchar(10),
Acost varchar(10)
);
GO
INSERT INTO myTable (Aid, Atype, Acost)
VALUES ('001', '1', '40'),
('002', '2', '80'),
('003', '3', '120')
GO
CREATE DATABASE myDatabase2;
GO
USE myDatabase2;
GO
CREATE TABLE myTable
(
Aid int,
Atype varchar(10),
Acost varchar(10)
);
GO
INSERT INTO myTable (Aid, Atype, Acost)
VALUES ('001', '1', '40'),
('002', '2', '80'),
('003', '3', '120'),
('004', '4', '160')
GO
Output -
For myDatabse1 -
Aid | Atype | Acost |
001 | 1 | 40 |
002 | 2 | 80 |
003 | 3 | 120 |
For myDatabase2 -
Aid | Atype | Acost |
001 | 1 | 40 |
002 | 2 | 80 |
003 | 3 | 120 |
004 | 4 | 160 |
Compare SQL Queries in Tables by using the EXCEPT keyword :
EXCEPT shows the distinction between 2 tables. it's wont to compare the variations between 2 tables.
Now run this query where we use the EXCEPT keyword over DB2 from DB1 -
SELECT * FROM myDatabase2.myTable
EXCEPT
SELECT * FROM myDatabase1.myTable
Output -
Aid | Atype | Acost |
004 | 4 | 160 |