SQL Server displays all database names, table names, and field names (SQL statements)

1. Get all database names:
Select name from Master .. sysdatabases order by name

2. Get all table names:
Select name from databasename .. sysobjects where xtype = 'U' order by name
Xtype = 'U': indicates all user tables;
Xtype = 's': indicates all system tables;

3. Get all field names:
Select name from syscolumns where id = object_id ('tablename ')
 
In ms SQL Server, you can use the following methods to query the disk space usage, database data files, log files, and Utilization:
 
1. query the remaining space of each disk partition:
Exec master. DBO. xp_fixeddrives

2. query the data files and log files of the database (including the file group, current file size, maximum file size, file growth settings, file logical name, and file path)
Select * from [database name]. [DBO]. [sysfiles]
The conversion file size is measured in MB:
Select name, convert (float, size) * (8192.0/1024.0)/1024. From [database name]. DBO. sysfiles
 
3. query the disk usage of the current database:
Exec sp_spaceused
 
4. query the size and utilization of log files of each database on the database server
DBCC sqlperf (logspace)