MultiplicationEach record of the table PupilsFor each record on the left, attempt to associate all records from MarksNameParentAddressNameSubjectMarkNoahMichael Wilson72 Oxford StreetNoahMathematicsB+NoahMichael Wilson72 Oxford StreetNoahDrawingB-Several kinds of JOINs. LEFT JOIN will keep records from the left table in case no association matches it.
Example: If a pupil doesn't have any mark yet, its record will still appear, and the columns on the right will be empty (NULL in SQL). INNER JOIN will filter out records which don't match. OUTER JOIN will be the same as the left join, except records from both sides, which don't match any association, will be retained. Join by listing tables with commas. Example: SELECT. FROM Pupils, Marks.
This is a less explicit form of joining, therefore I will not explain it here.The most intuitive form for beginners is the LEFT JOIN. Using the WHERE clause with LEFT JOINSo you have a student with no mark, such as the result of the query is.
Relational database programs, such as Microsoft Office Access, use SQL to work with data. Note: SQL is not only used for manipulating data, but also for creating and altering the design of database objects, such as tables. The part of SQL. SQL object tab showing a SELECT statement. SELECT clause. Access SQL: basic concepts, vocabulary, and syntax. This is one of a set of articles about Access SQL. This article describes the basic use of SQL to select data, and uses examples to illustrate SQL syntax. To combine the four fields from the two tables: SELECT name, price, warrantyavailable, exclusiveoffer FROM Products UNION ALL.