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I try to add a column in a table with swift.
my code :
connect_db();
adddbfield("mynewfield","mytable");
.
func connect_db() -> Bool {
let sDBPath=<is correctly set>;
if sqlite3_open(sDBPath, &db) != SQLITE_OK {
println("Failed to open db")
return false;
}else{
return true;
}
}
.
func adddbfield(sFieldName:String, sTable:String) -> Bool {
var bReturn:Bool=false;
var sSQL="ALTER TABLE " + sTable + " ADD COLUMN " + sFieldName + " INTEGER DEFAULT -1";
var statement:COpaquePointer = nil
if sqlite3_prepare_v2(db, sSQL, -1, &statement, nil) != SQLITE_OK {
println("Failed to prepare statement")
}else{
println("field " + sFieldName + " added to " + sTable);
bReturn=true;
}
return bReturn;
}
With this Code no field is added and no error occurs. Any help ? (I would like to use the native access to sqlite and no additional library)
306
How do I add multiple columns in SQLite? SQLite does not support adding multiple columns to a table using a single statement. To add multiple columns to a table, you must execute multiple ALTER TABLE ADD COLUMN statements.
Summary. Use the ALTER TABLE statement to modify the structure of an existing table. Use ALTER TABLE table_name RENAME TO new_name statement to rename a table. Use ALTER TABLE table_name ADD COLUMN column_definition statement to add a column to a table.
To insert data into a table, you use the INSERT statement. SQLite provides various forms of the INSERT statements that allow you to insert a single row, multiple rows, and default values into a table. In addition, you can insert a row into a table using data provided by a SELECT statement.
You are only preparing the statement, not executing it. You need to call sqlite3_step() and sqlite3_finalize() methods for completing the process.
func adddbfield(sFieldName:String, sTable:String) -> Bool
{
var bReturn:Bool = false;
var sSQL="ALTER TABLE " + sTable + " ADD COLUMN " + sFieldName + " INTEGER DEFAULT -1";
var statement:COpaquePointer = nil
if sqlite3_prepare_v2(db, sSQL, -1, &statement, nil) != SQLITE_OK
{
println("Failed to prepare statement")
}
else
{
if sqlite3_step(statement) == SQLITE_DONE
{
println("field " + sFieldName + " added to " + sTable);
}
sqlite3_finalize(statement);
bReturn=true;
}
return bReturn;
}
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