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3 Νοε 2017 · Let's consider as an example two database : DB_A and DB_B. Assume that in DB_A, there is a table named TBL1 I would like to create in DB_B a 'virtual table' DB_B.TBL1 which is linked to DBA.TBL1. When one table is updated, it's brother also.
27 Ιαν 2024 · A many-to-many relationship occurs when multiple records in one table are associated with multiple records in another table. This relationship is implemented using a ‘junction table’, which contains foreign keys that reference the primary keys in the associated tables.
Linking tables, also known as junction tables or associative tables, play a key role in implementing many-to-many relationships between entities. Example Let’s consider a scenario where you have two entities, such as “Students” and “Courses,” and each student can enroll in multiple courses, and each course can have multiple students.
You can move databases or tables from the database directory to other locations and replace them with symbolic links to the new locations.
You can move databases or tables from the database directory to other locations and replace them with symbolic links to the new locations.
A join is a method of linking data between one or more tables based on the values of the common column between the tables. MySQL supports the following types of joins: Inner join; Left join; Right join; Cross join; To join tables, you use the cross join, inner join, left join, or right join clause.
If the ID in your 'link' table absolutely has to be unique, and if it's ALWAYS a link between two IDs, you could use 3 columns: ID, min_position, max_position. That would allow you to use joins with your positions table.
