SQL INSERT INTO from multiple tables

user_2075019 0
Viewed 347358

this is my table 1:

NAME       AGE        SEX        CITY             ID

Clara      22         f          New York         1
Bob        33         m          Washington       2
Sam        25         m          Boston           3

this is my table 2:

NUMBER       ID
555-1111     1
555-2222     2
555-3333     3

and now I want a table 3 which shows me all information:

NAME       AGE        SEX        CITY             ID        NUMBER

Clara      22         f          New York         1         555-1111
Bob        33         m          Washington       2         555-2222
Sam        25         m          Boston           3         555-3333

I tried first to insert into table 3 only the values from table 1 and then I inserted into table 3 the values from table 2 with an inner join where Id = Id is.

INSERT INTO table3 { name, age, sex, city, id}
SELECT name, age, sex, city, id
FROM table 1



INSERT INTO table3 { name, age, sex, city, id, number}
SELECT name, age, sex, city, id, number
FROM table 2 p
INNER JOIN table 3 c ON c.Id = p.Id

But all I get is a duplication of my values. instead of having 3 entries, I have like 9 entries, which some have number null, some have only the number and the rest null, and some are correct.

I hope someone can help me

EDIT

If I am having now a third Table like this one:

NATIONALITY       ID

Canadian          1
American          2
French            3

How could I merge all 3 tables into one Table?

sql-server sql
7 Answers

You only need one INSERT:

INSERT INTO table4 ( name, age, sex, city, id, number, nationality)
SELECT name, age, sex, city, p.id, number, n.nationality
FROM table1 p
INNER JOIN table2 c ON c.Id = p.Id
INNER JOIN table3 n ON p.Id = n.Id
user_10818970

I would suggest instead of creating a new table, you just use a view that combines the two tables, this way if any of the data in table 1 or table 2 changes, you don't need to update the third table:

CREATE VIEW dbo.YourView
AS
    SELECT  t1.Name, t1.Age, t1.Sex, t1.City, t1.ID, t2.Number
    FROM    Table1 t1
            INNER JOIN Table2 t2
                ON t1.ID = t2.ID;

If you could have records in one table, and not in the other, then you would need to use a full join:

CREATE VIEW dbo.YourView
AS
    SELECT  t1.Name, t1.Age, t1.Sex, t1.City, ID = ISNULL(t1.ID, t2.ID), t2.Number
    FROM    Table1 t1
            FULL JOIN Table2 t2
                ON t1.ID = t2.ID;

If you know all records will be in table 1 and only some in table 2, then you should use a LEFT JOIN:

CREATE VIEW dbo.YourView
AS
    SELECT  t1.Name, t1.Age, t1.Sex, t1.City, t1.ID, t2.Number
    FROM    Table1 t1
            LEFT JOIN Table2 t2
                ON t1.ID = t2.ID;

If you know all records will be in table 2 and only some in table 2 then you could use a RIGHT JOIN

CREATE VIEW dbo.YourView
AS
    SELECT  t1.Name, t1.Age, t1.Sex, t1.City, t2.ID, t2.Number
    FROM    Table1 t1
            RIGHT JOIN Table2 t2
                ON t1.ID = t2.ID;

Or just reverse the order of the tables and use a LEFT JOIN (I find this more logical than a right join but it is personal preference):

CREATE VIEW dbo.YourView
AS
    SELECT  t1.Name, t1.Age, t1.Sex, t1.City, t2.ID, t2.Number
    FROM    Table2 t2
            LEFT JOIN Table1 t1
                ON t1.ID = t2.ID;
user_10484250

Try doing:

INSERT INTO table3(NAME,AGE,SEX,CITY,ID,NUMBER)
SELECT t1.name,t1.age, t1.sex,t1.city,t1.id,t2.number
FROM table1 t1
LEFT JOIN table2 t2 ON t1.id = t2.id

By using LEFT JOIN, this will insert every record from table 1 in table3, and for the ones that match the join condition in table2, it will also insert their number.

user_13858960

If I'm understanding you correctly, you should be able to do this in one query, joining table1 and table2 together:

INSERT INTO table3 { name, age, sex, city, id, number}
SELECT p.name, p.age, p.sex, p.city, p.id, c.number
FROM table1 p
INNER JOIN table2 c ON c.Id = p.Id
user_27515730
user_18627550
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