Converting a string to char array

Question

I couldn't find a perfect title for the problem but here it comes..Is there a way in which a string "hello" can be changed into a 'hello' in java (android)?? This is to make my sql query work. For example, here's my function written in java for an android app

public Cursor GetLecture(String course_code)
{
    SQLiteDatabase sqldb = this.getReadableDatabase();
    String query = "SELECT * FROM Lecture WHERE course_code =" + course_code;
    Cursor C = sqldb.rawQuery(query, null);
    return C;
}

The problem here is that what the query needs is for the value of the course_code to be for instance 'S11'and not "S11" which the variable course_code has as it is a string..So how can I change the string value which has double quote ("") to single quote ('') to make the query work? Is there a shorter way or I have to change the whole algorithm?? Thanks in advance for considering!!

Rohit Jain · Accepted Answer · 2013-10-14 08:11:32Z

2

Strings are sequence of characters delimited by double quotes. You can't delimit them by single quotes. Those are for characters. This one is in Java.

In case of SQL query, to enclose your string in single quotes, you can do it like this:

String query = "SELECT * FROM Lecture WHERE course_code = '" + course_code + "'";

answered Oct 14, 2013 at 8:11

Rohit Jain

214k45 gold badges419 silver badges534 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

user2878050 Over a year ago

Exactly the answer i was looking for, problem solved, thank you!!

Konstantin Yovkov · Accepted Answer · 2013-10-14 08:12:07Z

2

If you rewrite :

String query = "SELECT * FROM Lecture WHERE course_code =" + course_code;

as

String query = "SELECT * FROM Lecture WHERE course_code ='" + course_code + "'";

edited Oct 14, 2013 at 8:12

Konstantin Yovkov

63k9 gold badges107 silver badges152 bronze badges

answered Oct 14, 2013 at 8:11

Sergiu

2,6367 gold badges36 silver badges60 bronze badges

Comments

Community · Accepted Answer · 2017-05-23 11:57:20Z

1

There is a special construction to make the values in the query:

p_query = "select * from mutable where name_field = ?";
mDb.rawQuery(p_query, new String[] { fieldValue });

or you can simply add escape symbols and quotes

String query = "SELECT * FROM Lecture WHERE course_code = \"" + DatabaseUtils.sqlEscapeString(course_code) + "\"";

from here:

Android quotes within an sql query string

edited May 23, 2017 at 11:57

CommunityBot

11 silver badge

answered Oct 14, 2013 at 8:15

Mefistofel

464 bronze badges

Collectives™ on Stack Overflow

Converting a string to char array

3 Answers 3

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related