Develop Reference

Reset INTEGER PRIMARY KEY AUTOINCREMENT in Android

I created a table called DRINK. I inserted two rows in to it initially. When upgraded, I would like to delete both rows and reset my Primary Key to 1. I am getting the rows to delete but am not having any luck resetting the primary key. Does anybody know the syntax on how to do that or if it's even possible? Here's the function which is called from my onUpdate function:
private void updateMyDatabase(SQLiteDatabase db, int olderVersion, int newVersion){
Log.v("DatabaseHelper","UPDATE MY DATABASE");
if (olderVersion<1){
db.execSQL("CREATE TABLE DRINK (_id INTEGER PRIMARY KEY AUTOINCREMENT,"
+ "NAME TEXT, "
+ "DESCRIPTION TEXT, "
+ "IMAGE_RESOURCE_ID INTEGER);");
insertDrink(db,"latte","Espresso and Steamed Milk",R.drawable.latte);
insertDrink(db, "cappuccino", "This a Cappuccino", R.drawable.cap);
}
if (olderVersion < 2){
db.execSQL("delete from DRINK");
db.execSQL("alter table AUTO_INCREMENT =1"); //*** NEED HELP HERE***
insertDrink(db, "coff", "Espresso and Steamed Milk", R.drawable.latte);
}
}
I found this piece of code online but it's not working. Thank you.
db.execSQL("alter table AUTO_INCREMENT =1");

Deleteing the rows won't reset ROWID.
SQLite documentation states:
SQLite keeps track of the largest ROWID that a table has ever held
using the special SQLITE_SEQUENCE table. The SQLITE_SEQUENCE table is
created and initialized automatically whenever a normal table that
contains an AUTOINCREMENT column is created. The content of the
SQLITE_SEQUENCE table can be modified using ordinary UPDATE, INSERT,
and DELETE statements. But making modifications to this table will
likely perturb the AUTOINCREMENT key generation algorithm.
This sql should do what you need:
UPDATE SQLITE_SEQUENCE SET seq = <n> WHERE name = <table>
Where n is the sequence you wish to set and table is your table name

Defining columns in an SQLite Database table

I copied an SQLite Database example, where I created a table with 3 fields/columns and inserted one record with 3 values, as follows:
>SQLiteDatabase db = openOrCreateDatabase("MyDB",MODE_PRIVATE,null);
>db.execSQL("CREATE TABLE IF NOT EXISTS FunnyNames(Email VARCHAR(255), FirstName VARCHAR(255), LastName VARCHAR(255));");
>db.execSQL("INSERT INTO FunnyNames VALUES('abath#aol.com','Anita','Bath')");
..and I received this error message
>12-28 11:35:00.896: E/SQLiteLog(8857): (1) table FunnyNames has 1 columns but 3 values were supplied
didn't I define the columns correctly?

IF NOT EXISTS only creates the table if it didn't exist. Likely you already have a table with that given name in the database file, and that table only has 1 column.
Uninstall your app or clear its data in the app manager to remove the old database file. Or add DROP TABLE IF EXISTS FunnyNames before the CREATE TABLE.

You've missed the primary key of the table. Every table needs an primary key (which is an unique id) for referencing data. Modify your create statement as follow:
CREATE TABLE IF NOT EXISTS FunnyNames(_id INTEGER PRIMARY KEY AUTOINCREMENT, Email VARCHAR(255), FirstName VARCHAR(255), LastName VARCHAR(255));

INSERT OR IGNORE table with AUTOINCREMENT key in Android

I am trying to insert data to a new empty table. But I keep getting error (error code 19: constraint failed). I think the problem may caused by 'INTEGER PRIMARY KEY AUTOINCREMENT'. Here is my code:
database.execSQL("CREATE TABLE IF NOT EXISTS contacts (cid INTEGER PRIMARY KEY AUTOINCREMENT, name varchar NOT NULL, user varchar NOT NULL, UNIQUE(user) ON CONFLICT REPLACE)");
...
String sql = "INSERT OR IGNORE INTO contacts ( name , user) VALUES (?, ?)";
database.beginTransaction();
SQLiteStatement stmt = database.compileStatement(sql);
stmt.bindString(1, name);
stmt.bindString(2, entry.getUser());
int i = (int)stmt.executeInsert();
stmt.execute();
stmt.clearBindings();
stmt.close();
// error: 06-11 20:50:42.295: E/DB(12978): android.database.sqlite.SQLiteConstraintException: error code 19: constraint failed
Anyone knows what wrong with the sql statement? How can I solve this problem? Thanks
I have read few articles on stackoverflow. But cannot find anyone post related to 'insert or replace' + 'INTEGER PRIMARY KEY AUTOINCREMENT'.

I think your code is doing exactly what it is supposed to be doing. Reading over your code it looks like you want it to ignore inserts where there is already something inserted. The error you are receiving is telling you that the insert has failed.
If you use INSERT IGNORE, then the row won't actually be inserted if it results in a duplicate key. But the statement won't generate an
error. It generates a warning instead. These cases include:
Inserting a duplicate key in columns with PRIMARY KEY or UNIQUE
constraints. Inserting a NULL into a column with a NOT NULL
constraint. Inserting a row to a partitioned table, but the values you
insert don't map to a partition. - "INSERT IGNORE" vs "INSERT ... ON DUPLICATE KEY UPDATE"
I would recommend catching the SQLiteConstraintException or check before inserting to see if the data is already there. If you need some ideas on how to check if data has been inserted let me know, I have had to do this before. Hope this helps.

There is a good begining to end example of SQLite on Android written by Lars Vogella here
Inside there and down a little ways here is the string that he uses for creating a table:
// Database creation sql statement
private static final String DATABASE_CREATE = "create table "
+ TABLE_COMMENTS + "(" + COLUMN_ID
+ " integer primary key autoincrement, " + COLUMN_COMMENT
+ " text not null);";
I have not tried either his or yours just now but a few things I noticed that differ between his and yours are:
He has no space between the table name and the opening parenthesis
He has a semicolon inside of the SQL string. after the closing parenthesis.
I am not certain if those will fix it for you, but it would probably be a good start.

Duplicate Entries in SQLite

I am fetching and storing phone numbers and contact names in a SQLite DB from an Android phone. Now my problem is that whenever I refresh/reload the app the SQL entries (phone and contacts) are inserted again and again giving rise to duplicate entries. How to stop this, I am using Phonegap, by the way!
I am using this simple code to populate the DB
tx.executeSql('CREATE TABLE IF NOT EXISTS details (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, phone TEXT)');
But it is causing double entries.

Stopping this can be as easy as defining a two field primary key, like this :
CREATE TABLE contacts(
name CHAR(10) NOT NULL,
address INTEGER,
phone INTEGER NOT NULL,
song VARCHAR(255),
PRIMARY KEY (name, phone)
)
This key will ensure no entry in the database has the same name and phone.
Hope this helps !

It will solve the duplicate entry problem:
sampleDB.execSQL("INSERT OR REPLACE INTO measure_table (measure) " + "VALUES ( '" + "Length" + "')");

Android SQLite auto increment

I currently have a table called User which has a id column which is created as
'INTEGER PRIMARY KEY'
Lets say I have created two users so the table has id 1 and 2
If I delete the second user and create a third the id is 2, I need this to be 3
So it seems Android is selecting the next available id, how can I change this to its more like a sequence number?
Regards

Make it INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL. Here's what the docs say:
If a column has the type INTEGER PRIMARY KEY AUTOINCREMENT then... the ROWID chosen
for the new row is at least one larger than the largest ROWID that has
ever before existed in that same table.
The behavior implemented by the AUTOINCREMENT keyword is subtly
different from the default behavior. With AUTOINCREMENT, rows with
automatically selected ROWIDs are guaranteed to have ROWIDs that have
never been used before by the same table in the same database. And the
automatically generated ROWIDs are guaranteed to be monotonically
increasing.

SQLite AUTOINCREMENT is a keyword used for auto incrementing a value of a field in the table. We can auto increment a field value by using AUTOINCREMENT keyword when creating a table with specific column name to auto incrementing it.
The keyword AUTOINCREMENT can be used with INTEGER field only.
Syntax:
The basic usage of AUTOINCREMENT keyword is as follows:
CREATE TABLE table_name(
column1 INTEGER AUTOINCREMENT,
column2 datatype,
column3 datatype,
.....
columnN datatype,
);
For Example See Below:
Consider COMPANY table to be created as follows:
sqlite> CREATE TABLE TB_COMPANY_INFO(
ID INTEGER PRIMARY KEY AUTOINCREMENT,
NAME TEXT NOT NULL,
AGE INT NOT NULL,
ADDRESS CHAR(50),
SALARY REAL
);
Now, insert following records into table TB_COMPANY_INFO:
INSERT INTO TB_COMPANY_INFO (NAME,AGE,ADDRESS,SALARY)
VALUES ( 'MANOJ KUMAR', 40, 'Meerut,UP,INDIA', 200000.00 );
Now Select the record
SELECT *FROM TB_COMPANY_INFO
ID NAME AGE ADDRESS SALARY
1 Manoj Kumar 40 Meerut,UP,INDIA 200000.00

If speaking for ANDROID, yes, above answers are correct, except naming of the id column.
database.execSQL("CREATE TABLE IF NOT EXISTS "
+ TableName
+ " ( rowid INTEGER PRIMARY KEY AUTOINCREMENT, Raqam VARCHAR, ChandBor INT(3));");
It looks like in Android it should be named as 'rowid'.
And with Cursor you need to instantiate it like:
Cursor cursorLcl = database.rawQuery("SELECT *," + TableName + ".rowid AS rowid" + " FROM " +
TableName, null);
Otherwise it didnt work for me. I don't know why it so.

Just remember for android when writing tot the database (ie. executing),
do
INSERT INTO TABLE_NAME (param1name, param2name) VALUES (param1,param2)
and there is no need to add a place holder for the auto increment. It will add it by itself when adding a record. If you do not declare the params that you will put in, you will get the error x amount of variables expected and you only gave x-1, and this is because you are not supposed to give any place holding value for the auto increment column