- #Deleting column in db sqlite update#
- #Deleting column in db sqlite full#
- #Deleting column in db sqlite android#
nullvalue command tells the SQLite to show In such a case, we have to supply all values. In this SQL statement, we did not specify any column names after the table name. sqlite> INSERT INTO Cars VALUES(3, 'Skoda', 9000) Here is what we have in the Cars table at the moment. This means the SQLite library will add a new Id itself. INTEGER PRIMARY KEY and such columns are auto-incremented in sqlite> INSERT INTO Cars(Name, Price) VALUES('Mercedes', 57127) We have specified allĬolumn names after the table name and all values after the VALUES sqlite> INSERT INTO Cars(Id, Name, Price) VALUES(1, 'Audi', 52642) We create a new table Cars with Id, Name,Īnd Price columns. > Price INTEGER DEFAULT 'Not available') Sqlite> CREATE TABLE Cars(Id INTEGER PRIMARY KEY, Name TEXT, We will create a new table in which to execute our examples. The INSERT statement is used to insert data into tables. These statements are part of the SQL Data Manipulation
#Deleting column in db sqlite update#
We will use the INSERT, DELETE,Īnd UPDATE statements. In this part of the SQLite tutorial, we will insert, update and deleteĭata from SQLite tables. On my next posts I’ll publish some of my useful scripts to help me develop and test more efficiently.Contents Previous Next SQLite insert, update, delete data The badly-named columns days are over, no more columns like “task_title_which_is_shared_via_email”. That’s it! Let the columns’ dropping frenzy begin! You can also use this method to support the missing RENAME COLUMN command. We can also easily create a convenient function to receive only a String of one column name. The colsToRemove is an array of columns we want to remove from the table. The tableName is…well…the name of the table. You must have that command in order to create the table on a new installation of the app. The createTableCmd is the “CREATE TABLE… “ command to create the new table. This function is receiving the db and the connectionSource as arguments, as for the onUpgrade() method, which is the main entry point for the whole Database upgrading process. Using this, I wrote a function to get all the columns of a certain table: public List getTableColumns ( String tableName )
This will query the list of columns this table has, among with their properties (type, default value etc.). I solved this problem by using the following SQL command: PRAGMA table_info ( table_name ) I need to know the list of column I want to keep, instead of just the columns I want to remove. The main problem here – not a generic solution. That’s it, no more excuses! I’m dealing with this once and for all!įrom the SQlite’s FAQ page, one must follow these steps to get this done: BEGIN TRANSACTION CREATE TEMPORARY TABLE t1_backup ( a, b ) INSERT INTO t1_backup SELECT a, b FROM t1 DROP TABLE t1 CREATE TABLE t1 ( a, b ) INSERT INTO t1 SELECT a, b FROM t1_backup DROP TABLE t1_backup COMMIT I got myself into a situation where I needed to drop 4 column on 3 different tables.
#Deleting column in db sqlite full#
The Internet is full with with people asking about alternatives, and some got useful answers in the shape of pseudo code to get the table on its way to salvation. There were times where I considered leaving a redundant column in the table, just to avoid the whole process of removing it while upgrading :). The ALTER TABLE DROP COLUMN is one of the things I miss the most.
#Deleting column in db sqlite android#
In Android we use SQLite Database, and even though it supports many SQL commands as the more functional Databases around (MySql, Oracle…) it lacks a few useful commands. It’s irritating to write it, and even more irritating to test it afterwards (no matter how many useful scripts I wrote to make it easier). Lots of infrastructure changes, Some of them are Database changes, which I hate because then I have to support upgrading from older DB version. On the last couple of months I was working hard on that version. The new Any.DO version was released to beta testers this week.
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