SQL Server 2025 : T-SQL Basic Usage2026/03/24

# create [SampleDB] database
1> create database SampleDB; 
2> go 

# create a database with parameters
1> create database SampleDB2 
2> on primary ( name = 'SampleDB2',
3> filename = '/var/opt/mssql/data/SampleDB2.mdf',
4> size = 5GB, maxsize = unlimited, filegrowth = 10MB )
5> log on ( name = 'SampleDB2_log',
6> filename = '/var/opt/mssql/data/SampleDB2_log.ldf',
7> size = 1GB, maxsize = 2GB, filegrowth = 5% )
8> go

# list databases
1> select name,create_date from sys.databases;
2> go
name                          create_date
----------------------------- -----------------------
master                        2003-04-08 09:13:36.390
tempdb                        2026-03-24 10:33:16.060
model                         2003-04-08 09:13:36.390
msdb                          2026-02-25 21:40:26.777
SampleDB                      2026-03-24 10:38:26.657
SampleDB2                     2026-03-24 10:38:53.230

(6 rows affected)

# delete [SampleDB2] database
1> drop database SampleDB2; 
2> go 

# create [Sample_Table] table
1> create table dbo.Sample_Table ( 
2> Number nvarchar(10) not null, 
3> First_Name nvarchar(50) not null, 
4> Last_Name nvarchar(50) null, 
5> Last_Update date not null )
6> go 

# list tables
1> select name from sysobjects where xtype='u'
2> go 
name
--------------------------
Sample_Table

(1 rows affected)

# delete [Sample_Table] table
1> drop table dbo.Sample_Table; 
2> go 

# insert data
1> insert into dbo.Sample_Table ( Number, First_Name, Last_Name, Last_Update )
2> values ( '00001', 'RedHat', 'Linux', '2026-03-17' ),
3> ( '00002', 'Debian', 'Linux', '2026-03-17' ),
4> ( '00003', 'Ubuntu', 'Linux', '2026-03-17' )
5> go 

(3 rows affected)

1> select * from dbo.Sample_Table; 
2> go 
Number     First_Name      Last_Name     Last_Update    
---------- --------------- ------------- ----------------
00001      RedHat          Linux               2026-03-17
00002      Debian          Linux               2026-03-17
00003      Ubuntu          Linux               2026-03-17

(3 rows affected)

# show tables with specific columns
1> select Number, First_Name from dbo.Sample_Table; 
2> go 
Number     First_Name
---------- --------------------------
00001      RedHat
00002      Debian
00003      Ubuntu

(3 rows affected)

# show top 2 data
1> select top 2 * from dbo.Sample_Table; 
2> go 
Number     First_Name     Last_Name     Last_Update    
---------- -------------- ------------- ----------------
00001      RedHat         Linux               2026-03-17
00002      Debian         Linux               2026-03-17

(2 rows affected)

# update data
1> update dbo.Sample_Table set Last_Update = '2026-03-18' where First_Name = 'RedHat' 
2> go 

(1 rows affected)

1> select * from dbo.Sample_Table where First_Name ='RedHat'; 
2> go 
Number     First_Name    Last_Name     Last_Update    
---------- ------------- ------------- ----------------
00001      RedHat        Linux               2026-03-18

(1 rows affected)

# delete data
1> delete dbo.Sample_Table where First_Name ='Ubuntu'; 
2> go 

(1 rows affected)
1> select * from dbo.Sample_Table where First_Name ='Ubuntu'; 
2> go 
Number     First_Name    Last_Name     Last_Update
---------- ------------- ------------- ----------------

(0 rows affected)

name                     create_date
------------------------ -----------------------
master                   2003-04-08 09:13:36.390
tempdb                   2026-03-24 10:33:16.060
model                    2003-04-08 09:13:36.390
msdb                     2026-02-25 21:40:26.777
SampleDB                 2026-03-24 10:38:26.657
SampleDB2                2026-03-24 10:38:53.230

(6 rows affected)