是否有可能在运行时创建SQLite表基础上的数组元素的数量 [英] Is it possible to Create sqlite table at run time based on number of elements in array
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问题描述
我有一个不同的ArrayList列名。我想有一个generatized创建应根据我已通过数组列表创建表的方法。是否有可能有一个结构，可以动态地创建表。请提出任何解决方案。
私有静态类OpenHelper扩展SQLiteOpenHelper {
OpenHelper（上下文的背景下）{
超（背景下，DATABASE_NAME，空，DATABASE_VERSION）;
的System.out.println（openhelper1）;
}
@覆盖
公共无效的onCreate（SQLiteDatabase DB）{
Log.d（** DataHelper，***********在OnCreate中）;
db.execSQL（CREATE TABLE+ TABLE_NAME +（用户名文本，altnum TEXT，口令文本，标记文本））;
}
@覆盖
公共无效onUpgrade（SQLiteDatabase分贝，INT oldVersion，诠释静态网页）{
Log.w（榜样，升级数据库，这将删除表并重新创建。）;
db.execSQL（DROP TABLE IF EXISTS+ TABLE_NAME）;
的onCreate（DB）;
}
}
解决方案
我创建了自己的类来创建表和generatized地插入值。
公共无效createDynamicDatabase（上下文的背景下，字符串tableName值，ArrayList的＆LT;字符串＆GT;标题）{
Log.i（内部createLoginDatabase（）方法，************* creatLoginDatabase *********）;
尝试 {
INT I;
字符串querryString;
MyDatabase的= context.openOrCreateDatabase（DB，Context.MODE_WORLD_WRITEABLE，NULL）; //打开数据库的写入模式。
//System.out.println("Table名称：+ tableName.get（0））;
querryString = title.get（0）+VARCHAR（30），;
Log.d（** createDynamicDatabase，中的OnCreate）;
对于（i = 1; I＆LT; title.size（） - 1;我++）
{
querryString + = title.get（ⅰ）;
querryString + =VARCHAR（30）;
querryString + =;
}
querryString + = title.get（ⅰ）+VARCHAR（30）;
querryString =CREATE TABLE IF NOT EXISTS+ tableName值+（+ querryString +）;
的System.out.println（CREATE TABLE语句：+ querryString）;
myDataBase.execSQL（querryString）;
}赶上（前的SQLException）{
Log.i（CREATEDB异常，ex.getMessage（））;
}
}
公共无效插入（上下文的背景下，ArrayList的＆LT;字符串＆GT; array_vals，ArrayList的＆LT;字符串＆GT;标题字符串TABLE_NAME）{
Log.d（内部插入，插入的开始对表的名称：+ TABLE_NAME）;
MyDatabase的= context.openOrCreateDatabase（DB，Context.MODE_WORLD_WRITEABLE，NULL）; //打开数据库的写入模式。
字符串titleString = NULL;
字符串markString = NULL;
INT I;
titleString = title.get（0）+，;
？，markString =;
Log.d（** createDynamicDatabase，中的OnCreate）;
对于（i = 1; I＆LT; title.size（） - 1;我++）
{
titleString + = title.get（ⅰ）;
titleString + =;
？，markString + =;
}
titleString + = title.get（ⅰ）;
markString + =？;
//System.out.println("Title字符串：+ titleString）;
//System.out.println("Mark字符串：+ markString）;
INSERT =插入+ TABLE_NAME +（+ titleString +）+值+（+ markString +）;
的System.out.println（Insert语句：+ INSERT）;
//System.out.println("Array大小IIIIII :::+ array_vals.size（））;
//this.insertStmt = this.myDataBase.compileStatement（INSERT）;
INT S = 0;
而（S＆LT; array_vals.size（））{
的System.out.println（ARRAY1的大小+ array_vals.size（））;
阵列//System.out.println("Size+ title.size（））;
INT J = 1;
this.insertStmt = this.myDataBase.compileStatement（INSERT）;
对于（INT K = 0; K＆LT; title.size（）; k ++）
{
列//System.out.println("Value+标题+就是+ array_vals.get（K + S））;
//System.out.println("PRINT S：+ array_vals.get（K + S））;
的System.out.println（BindString：insertStmt.bindString（+ J +，+ array_vals.get（K + S）+））;
insertStmt.bindString（J，array_vals.get（K + S））;
J ++;
}
S + = title.size（）;
}
insertStmt.executeInsert（）;
}
I have a different arraylist with column names. I want to have a generatized create method that should create table based on the arraylist i have passed. Is it possible to have a structure with can create table dynamically. Please suggest any solution.
private static class OpenHelper extends SQLiteOpenHelper {
OpenHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
System.out.println("openhelper1");
}
@Override
public void onCreate(SQLiteDatabase db) {
Log.d("**DataHelper", "***********in oncreate");
db.execSQL("CREATE TABLE " + TABLE_NAME + " (username TEXT,altnum TEXT,passkey TEXT,flag TEXT)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w("Example", "Upgrading database, this will drop tables and recreate.");
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
}
解决方案
I created my own class to create tables and insert values in generatized manner.
public void createDynamicDatabase(Context context,String tableName,ArrayList<String> title) {
Log.i("INSIDE createLoginDatabase() Method","*************creatLoginDatabase*********");
try {
int i;
String querryString;
myDataBase = context.openOrCreateDatabase("Db",Context.MODE_WORLD_WRITEABLE, null); //Opens database in writable mode.
//System.out.println("Table Name : "+tableName.get(0));
querryString = title.get(0)+" VARCHAR(30),";
Log.d("**createDynamicDatabase", "in oncreate");
for(i=1;i<title.size()-1;i++)
{
querryString += title.get(i);
querryString +=" VARCHAR(30)";
querryString +=",";
}
querryString+= title.get(i) +" VARCHAR(30)";
querryString = "CREATE TABLE IF NOT EXISTS " + tableName + "("+querryString+");";
System.out.println("Create Table Stmt : "+ querryString);
myDataBase.execSQL(querryString);
} catch (SQLException ex) {
Log.i("CreateDB Exception ",ex.getMessage());
}
}
public void insert(Context context,ArrayList<String> array_vals,ArrayList<String> title,String TABLE_NAME) {
Log.d("Inside Insert","Insertion starts for table name: "+TABLE_NAME);
myDataBase = context.openOrCreateDatabase("Db",Context.MODE_WORLD_WRITEABLE, null); //Opens database in writable mode.
String titleString=null;
String markString= null;
int i;
titleString = title.get(0)+",";
markString = "?,";
Log.d("**createDynamicDatabase", "in oncreate");
for(i=1;i<title.size()-1;i++)
{
titleString += title.get(i);
titleString +=",";
markString += "?,";
}
titleString+= title.get(i);
markString += "?";
//System.out.println("Title String: "+titleString);
//System.out.println("Mark String: "+markString);
INSERT="insert into "+ TABLE_NAME + "("+titleString+")"+ "values" +"("+markString+")";
System.out.println("Insert statement: "+INSERT);
//System.out.println("Array size iiiiii::: "+array_vals.size());
//this.insertStmt = this.myDataBase.compileStatement(INSERT);
int s=0;
while(s<array_vals.size()){
System.out.println("Size of array1"+array_vals.size());
//System.out.println("Size of array"+title.size());
int j=1;
this.insertStmt = this.myDataBase.compileStatement(INSERT);
for(int k =0;k< title.size();k++)
{
//System.out.println("Value of column "+title+" is "+array_vals.get(k+s));
//System.out.println("PRINT S:"+array_vals.get(k+s));
System.out.println("BindString: insertStmt.bindString("+j+","+ array_vals.get(k+s)+")");
insertStmt.bindString(j, array_vals.get(k+s));
j++;
}
s+=title.size();
}
insertStmt.executeInsert();
}
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