Oracle SQL in 10 Minutes - Asim Abbasi
CH1: SQL Basics | CH2: SQL Operators | CH3: SQL Built-in Functions | CH4: SQL Joins | CH5: UPDATE, INSERT & DELETE Statements | CH6: CREATE, ALTER & DROP Statements | CH7: Constraints | CH8: Linking Tables vs Joining Tables | CH9: SQL Statements for Other Database Objects | CH10: SQL Statements for Database Security
Chapter 8: Linking Tables vs Joining Tables
Page #: 1
Difference between Linking & Joining Tables:
Like I said before, all the joins techniques we have learnt before viz.,
Outer Join, Equijoin etc. are at the query level can be implement on
tables having Primary/Foreign Key relationship or not.
Figure 17: Difference between joining & linking.
________________________________________
Implementing Primary/Foreign key relationship between two or more tables is also known as implementing Referential Integrity (RI) constraint between tose two or more tables.
The reason of bringing this topic up is, most beginners often get
confused when they read about joins and then primary key and foreign
key.
They think that join statements are only executed on tables linked
through primary and foreign key relationship but it’s not true.
The word “join” sometimes gives the feeling as if we are about to join
two or more tables permanently. Actually you are querying data from two
or more tables using of the techniques that fall under the title called
“Joins”.
Chapter 8: Linking Tables vs Joining Tables
Page #: 1
CH1: SQL Basics | CH2:
SQL Operators |
CH3: SQL Built-in Functions | CH4:
SQL Joins | CH5:
UPDATE, INSERT & DELETE Statements |
CH6: CREATE, ALTER & DROP Statements | CH7:
Constraints | CH8:
Linking Tables vs Joining Tables | CH9:
SQL
Statements for Other Database Objects | CH10:
SQL Statements for
Database Security Share with others: