SQL table, 2 columns and keys placement [closed]

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Here is a problem. I need to have 2 columns in a table both varchar(50). First Column is name of certain thing within a certain group which is defined by the second column.

First column | Second Column
thingone     | group one
thingtwo     | group one
thingone   开发者_JS百科  | group two

Above is an example which I want to achieve by having these to columns. And my question is how to place keys in order to do it. I know there is a easier way by having third column with id. But I am asking for possibilities looking similar to one above.

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You can make a primary key that contain's both columns.

Read the link's article http://weblogs.sqlteam.com/jeffs/archive/2007/08/23/composite_primary_keys.aspx

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You shouldn't store the name of your group in your table. You should create another table for groups, maybe called Groups and store your groups there, using GroupId and GroupName columns. Then in your main table, you should have a column named GroupId which only accepts the Id of the group, or technically speaking, is the foreign key to the Groups table.