Using string in whereClause on Android SQLite Query

Question

I am having a problem using a string in a SQLite Update query.

This code is not working .

 database.update(MySQLiteHelper.TABLE_NAME, values, MySQLiteHelper.COLUMN_TASKNAME + " = " + strName, null);

here strName is a string.

But this code works fine

database.update(MySQLiteHelper.TABLE_NAME, values, MySQLiteHelper.COLUMN_ID + " = " +  id , null);

Here id is an integer.

What is the difference between them?

BadIdeaException · Accepted Answer · 2014-03-15 18:47:16Z

2

When you're doing it like that, you need to add quotation marks around your string:

database.update(MySQLiteHelper.TABLE_NAME, values, MySQLiteHelper.COLUMN_TASKNAME + " = \"" + strName + "\"", null);

But you should probably really look into parameterized queries (using the selectionArgs in update like this:

database.update(MySQLiteHelper.TABLE_NAME, values, MySQLiteHelper.COLUMN_TASKNAME + " = ?", new String[] { strName })

It will make your database safer against SQL injection attacks.

answered Mar 15, 2014 at 18:47

BadIdeaException

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4 Comments

Abu Yousuf Over a year ago

Can you please explain why i should add quotation marks around string?

Abu Yousuf Over a year ago

+ always concate string and for integer it works fine

AdamM Over a year ago

The quotes are how sql lite databases identify it's a string. Integers can be taken literally. Read up on sql and it should say something in a section on queries

AXSM Over a year ago

Hello, i have been trying to make an update using parameters like that String whereClause = KEY_FIELD_CODE + “= ?” String whereArgs[] ={“123456″} But nothing works just update 0 rows, even if the rows who matches with the field exists. But the result change when i set the update statement like this: String whereClause = KEY_FIELD_CODE + “= 123456″ String whereArgs[] =null Does anyone knows why or in which cases we how. and the most important thing is how to fix that. Note: in this table in particular, im using a FTS3 para implementer full text search.. Thanks

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