3 SQL Statements to Get A Picture of Database Structure

When you have the needs to figure out a MS SQL database’s structure, here are 3 SQL statements that would give you a quick start. While they won’t give you a full picture of the whole database they are definitely going to lead you in a right direction with a quick view of what’s in there right now.

List the name of all the tables in a database

USE databasename
SELECT * FROM information_schema.tables ORDER BY TABLE_NAME

Replace the real database name in, you are off to go to get a list of tables in that database in the order of the table name.

List the column names of all the tables in a database

Now since we know how many tables in a database, let’s find out what the columns are in each table.

USE databasename
SELECT t.name AS table_name,
SCHEMA_NAME(schema_id) AS schema_name,
c.name AS column_name
FROM sys.tables AS t
INNER JOIN sys.columns c ON t.OBJECT_ID = c.OBJECT_ID 
ORDER BY schema_name, table_name;

If you need to know the column details in each table, do the following to each table:

exec sp_columns 'table1'
exec sp_columns 'table2'
...
...

List the tables with row counts and space consumption

If you are investigating a fairly large database, it would be helpful knowing what tables to look first. Execute the following statements and you will get a more clear picture of what you should look into first.

Use databasename
SELECT 
    t.NAME AS billings,
    s.Name AS SchemaName,
    p.rows AS RowCounts,
    SUM(a.total_pages) * 8 AS TotalSpaceKB, 
    SUM(a.used_pages) * 8 AS UsedSpaceKB, 
    (SUM(a.total_pages) - SUM(a.used_pages)) * 8 AS UnusedSpaceKB
FROM 
    sys.tables t
INNER JOIN      
    sys.indexes i ON t.OBJECT_ID = i.object_id
INNER JOIN 
    sys.partitions p ON i.object_id = p.OBJECT_ID AND i.index_id = p.index_id
INNER JOIN 
    sys.allocation_units a ON p.partition_id = a.container_id
LEFT OUTER JOIN 
    sys.schemas s ON t.schema_id = s.schema_id
WHERE 
    t.NAME NOT LIKE 'dt%' 
    AND t.is_ms_shipped = 0
    AND i.OBJECT_ID > 255 
GROUP BY 
    t.Name, s.Name, p.Rows
ORDER BY 
    t.Name

That’s about it. These statements have helped me a lot in number of occasions where I need to figure out a new database in order to do some customization. I hope they will help you too down the road.