5/17/2023 0 Comments Sqlite inner join![]() ![]() ![]() Here all the rows from tableX that is left side of JOIN clause and all the rows with NULL values for unmatched columns from tableY that is the right side of JOIN clause have appeared. LEFT OUTER JOIN tableY ON tableX.X= tableY.Y Here is LEFT OUTER JOIN SELECT tableX.*,tableY.* Here only the matching of both tableX and tableY have appeared in the result set. INNER JOIN tableY on tableX.X = tableY.Y In tableX the values ( A,B) are unique and in tableY the values (E,F) are unique, but the values (C and D) are common in both the tables. Here is two table tableX and tableY and they have no duplicate rows in each. The last one in FULL OUTER JOIN, in this join, includes the matching rows from the left and right tables of JOIN clause and the unmatched rows from left and right table with NULL values for selected columns. The second one is RIGHT OUTER JOIN, in this join includes all rows from the right of JOIN cause and the unmatched rows from the left table with NULL values for selected columns. The first one is LEFT OUTER JOIN, in this join includes all the rows from a left table of JOIN clause and the unmatched rows from a right table with NULL values for selected columns. This result set can appear in three types of format. Where as the OUTER JOIN returns all rows from the participating tables which satisfy the condition and also those rows which do not match the condition will appear in this operation. This type of join required a comparison operator to match rows from the participating tables based on a common field or column of both the tables. ON lumn_name= lumn_name Difference between INNER JOIN and OUTER JOINĪn INNER JOIN is such type of join that returns all rows from both the participating tables where the key record of one table is equal to the key records of another table. For example, retrieving all rows where the student identification number is the same for both the students and courses tables. Inner joins use a comparison operator to match rows from two tables based on the values in common columns from each table. the inner part of a Venn diagram intersection. An SQL INNER JOIN is same as JOIN clause, combining rows from two or more tables.Īn inner join of A and B gives the result of A intersect B, i.e. The INNER JOIN selects all rows from both participating tables as long as there is a match between the columns. JOIN returns all rows from tables where the key record of one table is equal to the key records of another table. Output: ITEM_ID ITEM_NAME ITEM_ COMPAN COMPAN COMPANY_NAME COMPANY_CITYĦ Cheez-It Pcs 15 15 Jack Hill Ltd LondonĢ BN Biscuit Pcs 15 15 Jack Hill Ltd LondonĤ Pot Rice Pcs 15 15 Jack Hill Ltd London To get all the columns from foods and company table after joining, with the following condition. Pictorial Presentation of SQL Inner Join of Company and Foods Tables: company id of foods and company id of company table must be same, To get item name, item unit columns from foods table and company name, company city columns from company table, after joining these mentioned tables, with the following condition -ġ. Output: ITEM_NAME ITEM_ COMPANY_NAME COMPANY_CITYĮxample of SQL INNER JOIN using JOIN keyword SQL Code: SELECT em_name,em_unit,Ĭpany_name,pany_city The following SQL statement can be used : company_id of foods and company table must be same, In this example the resulting objects are anonymous types that consist of the owner's first name and the pet's name.To join item name, item unit columns from foods table and company name, company city columns from company table, with the following condition -ġ. The select clause in C# defines how the resulting objects will look. The query uses the join clause in C# to match Person objects with Pet objects whose Owner is that Person. The following example creates two collections that contain objects of two user-defined types, Person and Pet. Record Dog(string Name, Person Owner) : Pet(Name, Owner) Īs well as the Student class from Query a collection of objects. Record Cat(string Name, Person Owner) : Pet(Name, Owner) Record Employee(string FirstName, string LastName, int EmployeeID) ![]() The examples in this topic use the following data classes: record Person(string FirstName, string LastName) ![]()
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