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 –
PHP
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.
PHP
CREATE DATABASE myDatabase1;GOUSE 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;GOUSE 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 – Aid Atype Acost 001 1 40 002 2 80 003 3 120
For myDatabse1 –
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 –
PHP
SELECT * FROM myDatabase2.myTableEXCEPTSELECT * FROM myDatabase1.myTable |
Output –
Aid | Atype | Acost |
004 | 4 | 160 |
