You can also opt for a unique index, as shown in the code below. There is a great need for a sarcasm font. You may also apply it directly as follows: CREATE TABLE users( usersid INTEGER UNIQUE, userage INTEGER ) If you have already created your table and need to add a modification to make any row unique, you will have to delete the whole table. I would assume SQLite also uses some kind of a sequence for PK You can define a UNIQUE constraint at the column or the table level. To define a UNIQUE constraint, you use the UNIQUE keyword followed by one or more columns. SQLite provides various forms of the INSERT statements that allow you to insert a single row, multiple rows, and default values into a table. Which hashid value do you use then?Īlso, Access uses something called 'AutoNumber' field as PK for a table, Oracle and SQL Server uses sequences to increment PK value in the tables. A UNIQUE constraint ensures all values in a column or a group of columns are distinct from one another or unique. To insert data into a table, you use the INSERT statement. The main reasons that differentiate each of these methods are: The ease of applying them. I want to insert records from first table to second in such a way that only unique records get inserted. Your 'pseudocode' logic may theoretically work if you always insert a record into the emailprops table related to the last record in email table, but is that always the case? You may have 100 records in email table, and you want to insert a record into emailprops table related to the 27th record in email table. In SQLite, there are multiple ways to avoid duplicate entries. It would be easy if it was just this entry, but I have more than 1,000 repeat entries, so it would take. As such it appears in the parttemp table more than once. The duplicate key value is (31335A11) partnum 31335A11 appears in the csv file more than once. But how do you know which record in emailprops table relates to which record in email table before you insert the record into emailprops table? And which hashid value to use as the value for compid in emailprops table? I don't think you can have this logic in the definition of the tables, you need to have it in the code that deals with INSERT INTO emailprops statements. Cannot insert duplicate key in object 'dbo.parts'. So in order to INSERT any record into emailprops table, you need to have a record in the email table. This will produce the following result, where there is no duplicate entry.Well, you have here Parent (email) - Child (emailprops) relationship between the 2 tables. Sqlite> SELECT DISTINCT name FROM COMPANY Now, let us use DISTINCT keyword with the above SELECT query and see the result. SELECT DISTINCT column1, lumnNĬonsider COMPANY table with the following records.įirst, let us see how the following SELECT query returns duplicate salary records. Syntaxįollowing is the basic syntax of DISTINCT keyword to eliminate duplicate records. 5 Easy Ways to Handle Duplicates Using SQL INSERT INTO SELECT. While fetching such records, it makes more sense to fetch only unique records instead of fetching duplicate records. SQLite DISTINCT keyword is used in conjunction with SELECT statement to eliminate all the duplicate records and fetching only the unique records. Inserting NULL primary keys into src causes them to be given auto-generated values. This example works because the table 'tmp' has no primary key constraint, but 'src' does. There may be a situation when you have multiple duplicate records in a table. I would set the default values for the dateadded fields instead of the trigger: CREATE TABLE email ( hashid INTEGER PRIMARY KEY, emailhash TEXT NOT NULL UNIQUE, hashdateadded DATETIME NOT NULL DFAULT DATETIME('NOW') ) CREATE TABLE emailprops ( propsid INTEGER PRIMARY KEY, compid INTEGER, propsdateadded DATETIME NOT NULL DFAULT DATETIME('NOW'), FOREIGN KEY (compid. To only duplicate a desired row, simply add a WHERE clause to the first line. SQLite DISTINCT keyword is used in conjunction with SELECT statement to eliminate all the duplicate records and fetching only the unique records. 4 Answers Sorted by: 31 Declare a unique constraint on (user, location).
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