Develop Reference

Issue deleting row from SQL Table

I'm trying to remove a row from an SQL table using this code below. However, whenever I call this method I get this following error:
android.database.sqlite.SQLiteException: no such column: Plumber (code 1): , while compiling: DELETE FROM service WHERE name = Plumber
public boolean deleteService(String name){
SQLiteDatabase db = this.getWritableDatabase();
boolean result = false;
String query = "SELECT * FROM "
+ TABLE_SERVICE
+ " WHERE "
+ COLUMN_NAME
+ " = \""
+ name
+ "\""
;
Cursor cursor = db.rawQuery(query, null);
if(cursor.moveToFirst()){
String nameStr = cursor.getString(0);
db.delete(TABLE_SERVICE, COLUMN_NAME + " = " + nameStr, null);
cursor.close();
result = true;
}
db.close();
return result;
}
This is my table
public void onCreate(SQLiteDatabase db){
String CREATE_USERS_TABLE = "CREATE TABLE " +
TABLE_SERVICE + "("
+
COLUMN_NAME + " TEXT," +
COLUMN_RATE + " TEXT," +
COLUMN_CATEGORY + " TEXT," + COLUMN_SUBCATEGORY + " TEXT)";
db.execSQL(CREATE_USERS_TABLE);
}

First you're fetching all the rows that in COLUMN_NAME have the value name.
Next you want to delete the 1st of these rows (maybe it's the only one?) because nameStr gets the value of the 1st column which is COLUMN_NAME.
Why are you doing this?
Just execute this statement:
int number = db.delete(TABLE_SERVICE, COLUMN_NAME + " = '" + name + "'", null);
if number gets the value 0 then no rows were deleted, else it gets the number of deleted rows.

delete deletes rows not columns.
If you want to get rid of a column, you need to drop it. The SQL syntax is:
alter table table_service drop column <column_name>;
I don't know how to express this in java with the methods that you are using.

Ensure that your SQL syntax is correct, and that "Plumber" is a string with double quotes. By my experience, these errors are usually caused by an incorrect column or name.
Use this format:
DELETE FROM table_name WHERE condition(s)
SQLite browser can also help you visualize your database.

Inserting Content Values in multiple tables in Sqlite Android Application

I am brand new to multiple tables in an SQLite database and am trying to find out what the best practices are for inserting values into multiple tables. My main question is do I need to Create another ContentValues object for inserting the values into a second table? I am really stumped on how to perform the insert(). Here is what I am trying so far.
Here are the two tables and schema
/* Creating a common attributes table here. */
private static final String CREATE_COMMON_ATTRIBUTES_TABLE = "create table "
+ COMMON_ATTRIBUTES_TABLE + "(" + DBColCons.UID_COMMON_ATTRIBUTES + " integer" +
" primary key autoincrement, " + DBColCons.GPS_POINT+ " integer not null, "
+ DBColCons.EXISTING_GRADE_GPS_POINT+ " integer not null, "
+ DBColCons.COVER+ " real not null, "+ DBColCons.NOTES+ " text, "
+ DBColCons.DATE+ " text)";
/* Creating a weld table here */
private static final String CREATE_WELD_TABLE = " create table " +WELD_TABLE+ "("
+ DBColCons.UID_WELD + " integer primary key, " + DBColCons.WELD_TYPE +
" text, " + DBColCons.WELD_ID + " text, " + DBColCons.DOWNSTREAM_JOINT +
" text, " + DBColCons.UPSTREAM_JOINT + " text, " + DBColCons.HEAT_AHEAD +
" text, " + DBColCons.LENGTH_AHEAD + " real, " + DBColCons.WALL_CHANGE +
" text, " + DBColCons.WELD_WALL_THICKNESS + " text, "
+ DBColCons.WELDER_INITIALS + " text, foreign key("+DBColCons.WELD_ID+") references" +
"("+DBColCons.GPS_POINT+"))";
Here is the method I am wanting to use for the insert() with some class getters() for the Weld class, which I am passing in as a parameter.
public boolean insertWeld(Weld weld) {
/* Get a writable copy of the database */
SQLiteDatabase db = this.getWritableDatabase();
/* Content values to insert with Weld class setters */
ContentValues contentValuesWeld = new ContentValues();
try {
contentValuesWeld.put(DBColCons.GPS_POINT, weld.getGpsPoint());
contentValuesWeld.put(DBColCons.WELD_TYPE, weld.getWeldType());
contentValuesWeld.put(DBColCons.WELD_ID, weld.getWeldId());
contentValuesWeld.put(DBColCons.DOWNSTREAM_JOINT, weld.getDownstreamJoint());
contentValuesWeld.put(DBColCons.UPSTREAM_JOINT, weld.getUpstreamJoint());
contentValuesWeld.put(DBColCons.HEAT_AHEAD, weld.getHeatAhead());
contentValuesWeld.put(DBColCons.LENGTH_AHEAD, weld.getLengthAhead());
contentValuesWeld.put(DBColCons.EXISTING_GRADE_GPS_POINT, weld.getExistingGradePoint());
contentValuesWeld.put(DBColCons.COVER, weld.getCover());
contentValuesWeld.put(DBColCons.WALL_CHANGE, weld.getWallChange());
contentValuesWeld.put(DBColCons.WELD_WALL_THICKNESS, weld.getWeldWallThickness());
contentValuesWeld.put(DBColCons.WELDER_INITIALS, weld.getWelderInitials());
contentValuesWeld.put(DBColCons.NOTES, weld.getNotes());
/* adding the date in here to the row. */
contentValuesWeld.put(DBColCons.DATE, String.valueOf(mStrDate));
/* Inserting into the weld table */
db.insertWithOnConflict(WELD_TABLE, DBColCons.WELDER_INITIALS, contentValuesWeld,
SQLiteDatabase.CONFLICT_NONE);
return true;
} catch (SQLException e) {
e.printStackTrace();
return false;
}
}
The values for DBColCons.GPS_POINT,DBColCons.EXISTING_GRADE_GPS_POINT,DBColCons.GPS_COVER and DBColCons.NOTES are what I want to insert into the Common_Attributes_Table. This is where I am really confused. Do I need to create a separate ContentValues object for those specific values and insert them into the desired table with a separate db.insert() method along with the one I am already using with the insert on the WELD_TABLE?
Help I am lost in this train wreck. Ha.
Thank you all.

You need to call insert() (or insertWithConflict()) for each table you are inserting values into. Unless the values are the same, this implies you will need another ContentValues per table.
If you intend for these inserts to be committed as a single atomic operation, consider using a transaction.
SQLiteDatabase db = ...;
db.beginTransaction();
try {
// do your inserts/etc. here
db.setTransactionSuccessful();
} finally {
db.endTransaction();
}

Query is not returning any data SQLite

I have database with 4 columns int id | String data | String date | int boot and i have some data in it. I have method getRow(String s) when i call it with string for id or data and change query to that option it works but when i´m trying to get row with equal date it won´t pass cursor.moveToFirst condition.
Here is my code:
String CREATE_TABLE = "CREATE TABLE "
+ TABLE_NAME + "(" + COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + COLUMN_DATA
+ " TEXT," + COLUMN_DATE + " TEXT," + COLUMN_BOOT + " Integer" + ")";
public String getRowID(String id){
SQLiteDatabase db = this.getReadableDatabase();
Cursor c = db.rawQuery("select * from " + TABLE_NAME + " where " + COLUMN_ID + " = " + id, null);
if (c != null && c.moveToFirst()) {
//loggin succes
return "string";
}else return null;
}
public String getRowDate(String date){
SQLiteDatabase db = this.getReadableDatabase();
Cursor c = db.rawQuery("select * from " + TABLE_NAME + " where " + COLUMN_DATE + " = " + date, null);
if (c != null && c.moveToFirst()) {
//loggin succes
return "string";
}else return null;
}
myDb.getRowID("1"); returning something
myDb.getRowDate("02122016"); returning null
I have two rows in my database.
1 | 0.19 | 01122016 | 0
2 | 0.19 | 02122016 | 0

Be wary when comparing integers and strings. You may wonder why SQLite would be comparing integers at all since your arguments are strings, until you consider that your raw query looks like this:
select * from TABLE where DATE = 02122016
That value is interpreted as an integer and converted to text, but it loses the leading zero in the process. You can verify this with a sqlite3 shell:
sqlite> select 02122016;
2122016
sqlite> select '02122016' = 02122016;
0 -- false
sqlite> select cast(02122016 as text);
2122016
The simplest fix is to quote the value using a method from DatabaseUtils:
String escaped = DatabaseUtils.sqlEscapeString(date);
String query = "select * from " + TABLE_NAME + " where " + COLUMN_DATE + " = " + escaped;
A better fix would be to use a placeholder argument instead. Note that Android binds all arguments as strings:
String query = "select * from " + TABLE_NAME + " where " + COLUMN_DATE + " = ?";
db.rawQuery(query, new String[]{date});
However, my advice would be to not use rawQuery() and instead use one of the real query() methods. Here's a good example.
Lastly, perhaps you should consider a different format for storing dates. In practice I usually either store an INTEGER column with a unix timestamp (seconds or milliseconds since epoch), or I use a TEXT column with values in the yyyy-MM-dd format since this is implicitly supported by numerous datetime functions in SQLite.

Android - SQlite insert not inserting

So i am trying to insert some data in the internal sqlite database but after i run the insert no data has been added. There are, as far as i can see no errors in the logs and every debug log i put into it is shown. If i try to run the query that is returned in the log in sqlitestudio it works without a problem so i haven't got a clue as to what is going wrong.
#Override
public void onCreate(SQLiteDatabase db) {
String SQL = pictureTable();
db.execSQL(SQL);
}
private String pictureTable() {
return "CREATE TABLE geophoto_db_pictures ( picid integer,"
+ "name varying character(50),"
+ "city varying character(20) NOT NULL,"
+ "zipcode varying character(20) NOT NULL,"
+ "country varying character(20) NOT NULL,"
+ "picdate datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,"
+ "tags varying character(200),"
+ "image varying character(200) NOT NULL,"
+ "uploaded integer NOT NULL DEFAULT 0, PRIMARY KEY (picid))";
}
#Override
public void savePicture(Picture pic) {
Log.d(LOG_TAG, "saving picture started. Data: " + pic.getName());
// clean the inputs
String name = pic.getName();
String city = pic.getCity();
if (city != null) {
city = "'" + city + "'";
}
String country = pic.getCountry();
if (country != null) {
country = "'" + country + "'";
}
String zip = pic.getZipcode();
if (zip != null) {
zip = "'" + zip + "'";
}
String tags = tagsToString(pic.getTags());
String image = pic.getImage();
// Insert Query, all possible null values on "not null" rows will be
// replaced by a default value.
String SQL = "INSERT INTO geophoto_db_pictures(name, city, zipcode, country, tags, image)"
+ "VALUES('"
+ name
+ "',"
+ "IFNULL("
+ city
+ ", 'Unknown')"
+ ","
+ "IFNULL("
+ zip
+ ", 'Unknown')"
+ ","
+ "IFNULL("
+ country + ",'Unknown')" + ",'" + tags + "','" + image + "')";
Log.d(LOG_TAG, SQL);
executeWriteQuery(SQL);
ArrayList<Picture> list = getAllPictures();
Log.d(LOG_TAG, "Size :"+list.size());
}
private Cursor executeWriteQuery(String query){
Log.d(LOG_TAG, "execute write query");
SQLiteDatabase db = getWritableDatabase();
Cursor response = db.rawQuery(query, null);
Log.d(LOG_TAG, "write query executed");
return response;
}
All tips/help greatly appreciated!
Thomas

Try to put a semicolon at the end of table creation query. In your case as show below
private String pictureTable() {
return "CREATE TABLE geophoto_db_pictures ( picid integer,"
+ "name varying character(50),"
+ "city varying character(20) NOT NULL,"
+ "zipcode varying character(20) NOT NULL,"
+ "country varying character(20) NOT NULL,"
+ "picdate datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,"
+ "tags varying character(200),"
+ "image varying character(200) NOT NULL,"
+ "uploaded integer NOT NULL DEFAULT 0, PRIMARY KEY (picid));";
}
While providing a query through an external String, you will need to provide SQL query with an end of statement ;. Using the primitive SQLite does not require ; as it just takes arguments and create function query itself. I have experienced both cases and I ended up understanding the way I have put it here.

The problem you are facing is that you are trying to use rawQuery() to insert a record, when you should be using execSQL() instead (see this answer).
So, the correct code for executeWriteQuery would be as follows:
private void executeWrite(String command){
Log.d(LOG_TAG, "execute write");
SQLiteDatabase db = getWritableDatabase();
db.execSQL(command);
Log.d(LOG_TAG, "write executed");
}
Also, consider using insert() instead as that will allow you to get a return value to determine whether or not the data was inserted successfully.

Android SQLite rawQuery with WHERE clause returns search string as column not found

I have created a table called CHEMISTID:
private static final String CREATE_TABLE_CHEMISTID = "CREATE TABLE "
+ CHEMISTID + "(" + KEY_ID + " INTEGER PRIMARY KEY, " + KEY_CHEMISTID
+ " TEXT" + ")";
My insert function works properly but when I run a search query to find if a chemistId is already present using the following query statement:
String selectQuery = "SELECT * FROM " + CHEMISTID +" WHERE " + KEY_CHEMISTID + " = "+ chemistID + ";";
Cursor c = db.rawQuery(selectQuery,null);
My logcat displays the following error message:
E/AndroidRuntime(1169): FATAL EXCEPTION: main
E/AndroidRuntime(1169): android.database.sqlite.SQLiteException: no such column: Spain (code 1): , while compiling: SELECT * FROM chemistIdTable WHERE chemistId = Spain;
Where Spain is a particular chemistId that I have dynamically created in my program.
How should I fix my selectQuery String so that it searches in the column name KEY_CHEMISTID for a particular String chemistId?

You need to quote your strings such as Spain in SQL so they get taken as string literals and not column name identifiers. You can use single quotes like 'Spain' for that.
However it's much better to use ? parameter placeholders instead and supply the parameter values in the selection args array, like:
... KEY_CHEMISTID + "=?" ...
c = db.rawQuery(selectQuery, new String[] { chemistID });

You missed single quote,So change
String selectQuery = "SELECT * FROM " + CHEMISTID +" WHERE " + KEY_CHEMISTID + " = "+ chemistID + ";";
to
String selectQuery = "SELECT * FROM " + CHEMISTID +" WHERE " + KEY_CHEMISTID + " = '"+ chemistID + "';";
Recommended solution is to use parameterized query as
Cursor c = db.query(CHEMISTID, null, KEY_CHEMISTID + "=?",
new String[] { chemistID },null, null, null, null);