C # determine access to build a library, build a table, file existence, etc.

1. Create a database

2. Determine if a table exists

3. Create a table

1.    CREATE DATABASE #region Access database operations
        private void Creatmdb (String dbName)
        {
             ADOX. Catalogclass cat = new ADOX. Catalogclass ();
            Cat. Create ("Provider=Microsoft.Jet.OLEDB.4.0;Data source=" + DbName + ";");
           //adox. Catalog cat = new Catalog ();
           //cat. Create ("Provider=Microsoft.Jet.OLEDB.4.0;Data source=" + DbName + "; Jet oledb:engine type=5 "); s
       }
         #endregion

   2.     #region Access database operations determine if a table exists in the database
         public bool Gettables (OleDbConnection conn)
        {
& nbsp;           int result = 0;
            DataTable schematable = conn. GetOleDbSchemaTable (OleDbSchemaGuid.Tables,
                                                                new object[] {null, NULL, NULL , "TABLE"});

if (schematable! = null)
{

for (Int32 row = 0; row < SchemaTable.Rows.Count; row++)
{
String col_name = schematable.rows[row]["table_name"]. ToString ();
if (col_name = = "Mychoosestock")
{
result++;
}
}
}
if (result = = 0)
return false;
return true;
}
#endregion

3. CREATE table #region Access database operations
Create a table for a new MDB, C # Operations Access creation table
Mdbhead is a ArrayList that stores the specific column names in table tables.
private void Createmdbtable (String mdbpath, String tableName, ArrayList mdbhead)
{
ADOX. Catalogclass cat = new ADOX. Catalogclass ();
String saccessconnection = @ "Provider=Microsoft.Jet.OLEDB.4.0; Data source= "+ mdbpath;
Connection = new OleDbConnection (saccessconnection);
Connection. Open ();
ADODB. Connection cn = New ADODB. Connection ();
cn. Open (saccessconnection, NULL, NULL,-1);

            Cat. ActiveConnection = cn;
           //Create a new table, C # manipulate Access's creation table
             ADOX. Tableclass tbl = new ADOX. Tableclass ();
            tbl. ParentCatalog = cat;//directory
            tbl. Name = TableName;

Add an auto-growing field
ADOX. Columnclass col = new ADOX. Columnclass ();
Col. ParentCatalog = cat;
Col. Type = ADOX. Datatypeenum.adinteger; field type must be set first
Col. Name = "id";
Col. properties["Jet oledb:allow Zero Length"]. Value = false;
Col. properties["AutoIncrement"]. Value = true;
Tbl. Columns.Append (col, ADOX. Datatypeenum.adinteger, 0);

Add a text field
int size = Mdbhead.count;
for (int i = 0; i < size; i++)
{
Add a text field
ADOX. Columnclass col2 = new ADOX. Columnclass ();
Col2. ParentCatalog = cat;
Col2. Name = Mdbhead[i]. ToString (); The name of the column
Col2. properties["Jet oledb:allow Zero Length"]. Value = false;
Tbl. Columns.Append (col2, ADOX. Datatypeenum.advarwchar, 500);
}
Set Primary key
Tbl. Keys.append ("PrimaryKey", ADOX. Keytypeenum.adkeyprimary, "id", "", "" ");

Cat. Tables.append (TBL); This sentence joins the table to the database (very important), C # Operations The CREATE table for access
TBL = null;
cat = null;
Connection. Close ();
}
#endregion

4.

Using System.Data;
Using System.Data.OleDb;

Using ADOX; You need to add Microsoft ADO Ext. 6.0 ***security

protected override void Buttonok_click (object sender, EventArgs e)
{

private OleDbConnection connection;

Private OleDbDataAdapter dataAdapter;

String systempath = Environment.getfolderpath (Environment.SpecialFolder.System);
if (directory.exists (Systempath + "\\data") = = false)//create the file folder if it does not exist
{
Directory.CreateDirectory (Systempath + "\\data");
}
String Favoritestockmdb = Systempath + "\\data\\Data.mdb";
if (! File.exists (Favoritestockmdb)) Creatmdb (Favoritestockmdb);//Determine if there is a database, does not exist, create
Connection =
New OleDbConnection (@ "Provider=Microsoft.Jet.OLEDB.4.0;Data source=" + favoritestockmdb);
Connection. Open ();

if (! Gettables (Connection))
{
String table_name = "Mychoosestock";
ArrayList col_names = new ArrayList ();
Col_names. ADD ("Stockcode");
Createmdbtable (FAVORITESTOCKMDB, TABLE_NAME, col_names);
Connection. Open ();
}
DataAdapter = new OleDbDataAdapter ("SELECT * from Mychoosestock", connection);
DataSet Datasetselect = new DataSet ();
DataAdapter.Fill (Datasetselect, "sel");
DataTable datatable = datasetselect.tables["sel"];
for (int i = 0; i < DataTable.Rows.Count; i++)
{
Listselect.add (Datatable.rows[i][1]. ToString ());
}
OleDbCommand InsertCommand = connection. CreateCommand ();
InsertCommand.CommandText = "INSERT into Mychoosestock (Stockcode) VALUES (?)";
INSERTCOMMAND.PARAMETERS.ADD ("Stockcode", OleDbType.VarChar, 1024);
Insertcommand.prepare ();
Insertcommand.parameters[0]. Value = list[0];
Int32 row = Insertcommand.executenonquery ();
if (row! = 0)
{
Messageboxhelper.showinfo ("The collection is successful!" ");
}
Else
{
Messageboxhelper.showinfo ("Collection failed! ");
}
Connection. Close ();

}

C # determine access to build a library, build a table, file existence, etc.