Interview question based on sql query

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In my previous interview , interviewer asked me about sql query

suppose i have student databse & it contain 10 tables

i want to find an rows from tables containing specific word .

Restrictions as below

1. I don't have table name
2. I don't have column name
3. I just have Database name & the word to be searched.

Is this possible to do? if yes can u plz share the query

Thanks for Help......

Posted 3-Feb-14 6:57am

patil.nitin8358

Updated 3-Feb-14 17:52pm

v6

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Yvan Rodrigues · Answer 1 · 2014-02-03T07:44:00

To the best of my knowledge, you would first need to query to get the names of the tables and columns.

There isn't a standardized SQL way to do this, but most RDBMS implementations do offer a way to do it. This is called metadata or schema querying. Sometimes the RDBMS provides helpers to do this, sometimes it exposes the schema as a table or view that can be queried. For example:

MySQL

SQL

SHOW TABLES;
SHOW COLUMNS IN Customers;

or

SQL

SELECT table_name FROM INFORMATION_SCHEMA.TABLES;
SELECT COLUMN_NAME, DATA_TYPE, IS_NULLABLE, COLUMN_DEFAULT 
    FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = 'Customers';

T-SQL

SQL

SELECT * FROM information_schema.tables; /* SQL Server >= 2005 */
SELECT * FROM sysobjects WHERE xtype='U'; /* SQL Server < 2005; U == User table */
SELECT COLUMN_NAME, DATA_TYPE, IS_NULLABLE, COLUMN_DEFAULT
    FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name = 'Customers';

Sandeep Singh Shekhawat · Answer 2 · 2014-02-03T18:02:00

I think, He/She is targeting something like:

Full text indexing is a great feature that solves a database problem, the searching of textual data columns for specific words and phrases in SQL Server databases. Full Text Index can be used to search words, phrases and multiple forms of word or phrase using FREETEXT() and CANTAINS() with “and” or “or” operators.

http://blog.sqlauthority.com/2008/09/05/sql-server-creating-full-text-catalog-and-index/[^]

Thava Rajan · Answer 3 · 2014-02-03T18:20:00

I am not sure why the interviewer ask this kind of question
but as per the question the following query will produce
the result in MssqlServer 2005 and above

SQL

USE <databasename>
DECLARE @word AS VARCHAR(100) ='Test'
DECLARE @sql AS NVARCHAR(MAX) =''
SELECT @sql = @sql + ISNULL('SELECT * FROM ['+T.name+'] WHERE  '+STUFF((
        SELECT 'OR  ['+c.[name]+'] like ''%'+@word +'%'' '
        FROM   sys.[columns] AS c
        WHERE  TYPE_NAME(c.system_type_id) IN ('varchar', 'nvarchar', 'char', 'text', 'ntext') AND
               c.[object_id] = t.[object_id]
               FOR XML PATH('')
       ), 1,3,'') +';
       ','')
FROM   sys.tables AS t
EXEC sp_executesql @sql</databasename>

Interview question based on sql query

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MySQL

T-SQL

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