how can get data from two tables?

Question

Hi All, How can get the data from two tables with out having the forigen key constraints? please help me Thanks to all

Dharmraj Thakur · Answer

Joins are meaningless without having a relationship (Not necessary to create the foreign key). Use joins when any table having a reference to another table. If a relationship between tables is not there then you can use union or other ways to get mixed data.

Piyush Pansuriya · Answer

Hi, Both table have common column to join the table, no need to primary key or forigen key. Columns : ID, Name , Address Columns : ID, Dept, Desig. SELECT * FROM INNSER JOIN ON table1.ID = table2.ID

Sumit Chaudhary · Answer

You can not use join and because of there is no forigen key and can Union use same data type should be same like select City from table1 Union select City from table2

Bharathi Raja · Answer

SELECT column list> FROM TABLE1 JOIN TABLE2 USING ( column name )

Sumit Chaudhary · Answer

Can you please explained table structure and how data you want.?

Hakan Axheim · Answer

Of course you can use UNION / UNION ALL but I think it's better to use INNER JOIN if you want to fetch data from totally different tables. An INNER JOIN is used to combine two tables into a new table. A UNION is used to combined rows into a new row. Duplicated rows are elimated when using UNION. Performance is actually almost the same. For better performance use indexes.

Hakan Axheim · Answer

You have several options to do that! The old fashion way is. SELECT alias1.col1,alias2.col1 FROM table1 as alias1, table2 as alias2 WHERE alias1.col1 = alias2.col2; The new way to join two tables is: SELECT table1.col1,table2 col1 FROM table1 INNER JOIN table2 ON (table1.col1 = table2.col1)

Piyush Agarwal · Answer

Use Joins...... thats the best way

chaithanya k · Answer

Two fetch records from Two tables There are two ways 1.Union and Union All 2.Joins 1.Using Union and Union All needs the same table to have similar schematic structure 2.Using joins the both the table should have atleast one column to be having identical values from both the tables.

Shefali Mishra · Answer

U can use joins or else u can use Union /Union All

Shahriar Nikkhah · Answer

try to find a relational field(s) in between both tables, so lets assume the related field is F1 If you are 100% sure that this is the right key just use the right JOIN if not you must study and understand the data, to do that 1 - use a inner join on f1 2- use a right join on f1 3- user a left join on f1 now check the number of orphan records and parent without child, this approch will help you to validate the selected field (f1) in your joins good luck

how can get data from two tables?

Answers (11)