So I'm trying to fetch data from one of my database tables, could you please check this out for me and see if you can spot the error?
SQLiteDatabase db = SQLiteDatabase.openDatabase(DB_PATH, null,
SQLiteDatabase.OPEN_READONLY);
Cursor cursor = db.query(TABLE_CLASSES, new String[] { TABLE_C_DAY,
TABLE_C_NAME, TABLE_C_DAY, TABLE_C_LOCATION, TABLE_C_TIMEHR,
TABLE_C_TIMEMIN, TABLE_C_DURATION, TABLE_C_ONETIMEEVENT,
TABLE_C_CTYPE, TABLE_C_OCCURINGWEEK}, TABLE_C_DAY + "=?",
new String[] { String.valueOf(day) }, null, null, null, null);
Okay so DB_PATH is definitely correct. I tried to close the db connection and it works fine so db works fine and exists.
All of the table column names are correct as these were used in onCreate to create the db and that worked fine. I also tried using
db.rawQuery("SELECT * FROM " + TABLE_CLASSES + " WHERE day = ?", new String[] { String.valueOf(day) });
So when I make the query the app stops and I get a Source code not found message in Eclipse. LogCat says that table 'classes' doesn't exist.
I tried the creation code manually and it worked. Here is the code from onCreate(SQLiteDatabase db);
String CREATE_DB_WITH_INIT_VALUES =
"CREATE TABLE %1$s (%4$s TEXT);" +
"INSERT INTO %1$s VALUES('Lecture');" +
"INSERT INTO %1$s VALUES('Lab');" +
"INSERT INTO %1$s VALUES('Tutorial');" +
"INSERT INTO %1$s VALUES('Meeting');" +
"INSERT INTO %1$s VALUES('Examples Class');" +
"CREATE TABLE %2$s (%5$s smallint, %6$s varchar(40), %7$s varchar(10), %8$s smallint, %9$s smallint, %10$s smallint, %11$s boolean, %12$s smallint, %13$s smallint);" +
"INSERT INTO %2$s VALUES(1,'COMP12112 Computation',1.1,9,0,60,'False','Lecture',3);" +
"INSERT INTO %2$s VALUES(1,'COMP16212 Java OOP 2',1.1,11,0,45,'False','Lecture',3);" +
"INSERT INTO %2$s VALUES(1,'COMP18111 Distributed Systems','Unix',13,15,60,'False','Lab',3);" +
"INSERT INTO %2$s VALUES(2,'Tutorial','LF13',15,0,60,'False','Tutorial',3);" +
"INSERT INTO %2$s VALUES(2,'COMP14111 AI','LF31',10,30,60,'False','Lab',3);" +
"CREATE TABLE %3$s (%14$s smallint, %15$s smallint, %16$s TEXT, %17$s date);";
CREATE_DB_WITH_INIT_VALUES = String.format(CREATE_DB_WITH_INIT_VALUES, TABLE_CLASS_TYPES,
TABLE_CLASSES, TABLE_DEADLINES, TABLE_CT_TYPE,
TABLE_C_DAY, TABLE_C_NAME, TABLE_C_LOCATION, TABLE_C_TIMEHR, TABLE_C_TIMEMIN, TABLE_C_DURATION,
TABLE_C_ONETIMEEVENT, TABLE_C_CTYPE, TABLE_C_OCCURINGWEEK,
TABLE_D_TIMEHR, TABLE_D_TIMEMIN, TABLE_D_DTEXT, TABLE_D_DDATE
);
db.execSQL(CREATE_DB_WITH_INIT_VALUES);
This code doesn't crash and all seems fine but then during the query the table can't be found.
Any idea what is wrong?
What you've done is a valid list of SQL statements. The real problem here is that the method execSQL() only allows you the execution of a single sql statement (See documentation here).
If you want to execute multiple statements automatically, I'd write a method that first splits those statements (by the ending semicolon of each one) and then execute each one in a loop, checking for errors in every iteration so that when some sql statement fails, you can throw a SQLException indicating the sql statement that failed. Something like this:
public static void execSQLScript(SQLiteDatabase db, String script) throws SQLException {
String[] statements = script.split(";");
db.beginTransaction();
for(String statement : statements) {
try {
db.execSQL(statement); // Seems like this method already throws a decent exception
}
catch(SQLException e) {
db.endTransaction(); // Rolling back the changes done
throw e;
}
}
db.setTransactionSuccessful(); // Not rolling but commiting changes, since everything went fine.
db.endTransaction();
}
I'm not a SQL expert but I think your trying to do a little too much when creating the tables. I would suggest creating the table and adding any initial data in 2 different steps.
I don't have any initial data in my database but this is what I'm using to create the table:
createTable = "CREATE TABLE " + TABLE_NAME + "(" + COLUMN_ID + " INTEGER PRIMARY KEY," +
COLUMN_ONE + " TEXT," + COLUMN_TWO + " INTEGER," + COLUMN_THREE + " TEXT," +
COLUMN_FOUR + " TEXT," + COLUMN_FIVE + " TEXT)";
db.execSQL(createTable);
Now in your case after creating the table you can then insert the initial data you want. After
db.execSQL(createTable);
use a ContentValues to add the data you need to the database.
contentValues = new ContentValues();
contentValues.putXXX();
// keep adding data
// the insert method will add the data for you.
SQLiteDatabase.insert(TABLE_NAME, null, contentValues);
Related
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.
I am working on an android application that uses two databases. Recently, I had to add a new column to one of the databases. Upon doing so, it broke my database. Installing and re-installing the application on my device did nothing, and I also updated the DB version.
Trying to insert data will net me this error:
E/SQLiteLog﹕ (1) table message_table has no column named msg_type
So, I tried taking out the "msg_type" column from the insert, and inserting data which gave me this error:
E/SQLiteLog﹕ (1299) abort at 8 in [INSERT INTO message_table(recipient,message) VALUES (?,?)]: NOT NULL constraint failed: message_table.msg_typeTEXT
Here is the oncreate:
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE IF NOT EXISTS " + TABLE_NAME + " (" +
COL_1 + " INTEGER PRIMARY KEY AUTOINCREMENT, " + //msg_id
COL_2 + " TEXT NOT NULL, " + //recipient
COL_3 + " TEXT, " + //message
COL_4 + "TEXT NOT NULL);"); //message type
}
and the insert class:
public boolean addMessage(String recipient, String message, String type){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
//populate message object
contentValues.put(COL_2, recipient);
contentValues.put(COL_3, message);
contentValues.put(COL_4, type);
//insert new message
long result = db.insert(TABLE_NAME, null, contentValues);
//check if operation was successful
if(result == -1)
return false;
else
return true;
}
How can I be getting an error for either case? I thought that it didn't recognize the new column was added from the first error, but it also doesn't like not receiving the data for that column.
The error is happening because there is no space between the column name and the TEXT. So the column name becomes message_table.msg_typeTEXT:
COL_4 + "TEXT NOT NULL);"); //message type
This should fix the error:
COL_4 + " TEXT NOT NULL);"); //message type
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.
I am trying to make a variable Table name through Java.
My code is :
public void createTable(String tableName){
try {
Statement stmt = con.createStatement();
stmt.executeUpdate("CREATE TABLE '"+tableName+"'" +
"(id INTEGER not NULL, " +
" username VARCHAR(255), " +
" pass VARCHAR(255), " +
" age INTEGER, " +
" PRIMARY KEY ( id ))");
}
catch (SQLException e){
e.printStackTrace();
}
}
It gives me a syntax error saying:
Incorrect syntax near 'VariableTableNameIChose'.
Does anyone have any ideas?
It could be one of 2 things or the combination of both.
Maybe the single quotes around the table name are not valid in your database. So do like this:
stmt.executeUpdate("CREATE TABLE "+tableName+" " +
"(id INTEGER not NULL, " +
" username VARCHAR(255), " +
" pass VARCHAR(255), " +
" age INTEGER, " +
" PRIMARY KEY ( id ))");
Or maybe you need a spaces between the table name and the ( following after:
Statement stmt = con.createStatement();
// v this one was missing
stmt.executeUpdate("CREATE TABLE '"+tableName+"' " +
"(id INTEGER not NULL, " +
" username VARCHAR(255), " +
" pass VARCHAR(255), " +
" age INTEGER, " +
" PRIMARY KEY ( id ))");
The table name is an identifier. Identifiers do not use single quotes (in standard SQL).
"CREATE TABLE '"+tableName+"' "
Will result in
CREATE TABLE 'foobar'
which is invalid SQL. You need to remove the single quotes:
"CREATE TABLE "+tableName+" " + ...
As the table name is apparently a user input, you might actually want to use quoted identifiers (although this is in general a bad idea). Identifiers are quoted using double quotes in the SQL standard:
"CREATE TABLE \""+tableName+"\" " + ...
I have an application in Android (running 4.0.3) that stores a lot of data in Table A. Table A resides in SQLite Database. I am using a ContentProvider as an abstraction layer above the database.
Lots of data here means almost 80,000 records per month. Table A is structured like this:
String SQL_CREATE_TABLE = "CREATE TABLE IF NOT EXISTS " + TABLE_A + " ( " +
COLUMN_ID + " INTEGER PRIMARY KEY NOT NULL" + "," +
COLUMN_GROUPNO + " INTEGER NOT NULL DEFAULT(0)" + "," +
COLUMN_TIMESTAMP + " DATETIME UNIQUE NOT NULL" + "," +
COLUMN_TAG + " TEXT" + "," +
COLUMN_VALUE + " REAL NOT NULL" + "," +
COLUMN_DEVICEID + " TEXT NOT NULL" + "," +
COLUMN_NEW + " NUMERIC NOT NULL DEFAULT(1)" + " )";
Here is the index statement:
String SQL_CREATE_INDEX_TIMESTAMP = "CREATE INDEX IF NOT EXISTS " + TABLE_A +
"_" + COLUMN_TIMESTAMP + " ON " + TABLE_A + " (" +
COLUMN_TIMESTAMP + ") ";
I have defined the columns as well as the table name as String Constants.
I am already experiencing significant slow down when retrieving this data from Table A. The problem is that when I retrieve data from this table, I first put it in an ArrayList and then I display it. Obviously, this is possibly the wrong way of doing things. I am trying to find a better way to approach this problem using a ContentProvider. But this is not the problem that bothers me.
The problem is for some reason, it takes a lot longer to retrieve data from other tables which have only upto 12 records maximum. I see this delay increase as the number of records in Table A increase. This does not make any sense. I can understand the delay if I retrieve data from Table A, but why the delay in retrieving data from other tables.
To clarify, I do not experience this delay if Table A is empty or has less than 3000 records.
What could be the problem?
EDIT: 09/14/2012 9:53 AM
To clarify, I am using a ContentProvider to manage the database. To query the data, I am using the context.getContentResolver().query method.
My query code in the ContentProvider:
#Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
final SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
final SQLiteDatabase db = dbHelper.getReadableDatabase();
String tableName = getTableName(uri);
queryBuilder.setTables(tableName);
Cursor cursor = queryBuilder.query(db, projection, selection, selectionArgs, null, null, sortOrder);
cursor.setNotificationUri(getContext().getContentResolver(), uri);
return cursor;
}
So this is embarrassing:
Apparently, there was one line of code somewhere during the Application Load that was retrieving data from Table A. That was what was slowing down the application as a whole.
In any case, I still have to figure out how to optimize loading data from Table A using a ContentProvider.