Question

I have two databases in MySQL and SQL Server, and I want to create tables in SQL Server and copy all rows from the table in MySQL into the new table in SQL Server.

I can create table in SQL Server same as MySQL, with this code:

List<String> TableNames = new List<string>();
{ 
    IDataReader reader= 
        ExecuteReader("SELECT Table_Name FROM information_schema.tables WHERE table_name LIKE 'mavara%'",MySql);
    while (reader.Read()) {
        TableNames.Add(reader[0].ToString());
    }
    reader.Close();
}

foreach (string TableName in TableNames) {
    IDataReader reader = 
        ExecuteReader("SELECT Column_Name,IS_NULLABLE,DATA_TYPE FROM information_schema.columns where TABLE_Name='" + TableName + "'",MySql);
    List<string[]> Columns = new List<string[]>();
    while (reader.Read()) { 
        string[] column = new string[3];
        column[0] = reader[0].ToString();
        column[1] = reader[1].ToString();
        column[2] = reader[2].ToString();
        Columns.Add(column);
    }

    reader.Close();

    // create table
    string  queryCreatTables=  "CREATE TABLE [dbo].[" + TableName + "](\n";
    foreach(string[] cols in Columns)
    {
        queryCreatTables +="["+ cols[0] + "] " + cols[2] + " ";
        if (cols[1] == "NO")
            queryCreatTables += "NOT NULL";
        // else
        //   queryCreatTables += "NULL";
        queryCreatTables += " ,\n ";
    }
    queryCreatTables += ")";

    System.Data.SqlClient.SqlCommand smd = 
        new System.Data.SqlClient.SqlCommand(queryCreatTables, MsSql);
    System.Data.SqlClient.SqlDataReader sreader = smd.ExecuteReader();
    sreader.Close();

but I have problem to copy rows from one table into another table.

for select query, I use Idatareader, but I don’t know how insert rows to another table.

Answer 1

The algorithm is as follows:

1. For each table in source database
2.    Get a list of columns for that table
3.    Create table in destination database
4.    SELECT * FROM the table in source
5.    For each row in data
6.       Generate INSERT statement and execute on destination database

The information you need for a column is Name, Type, Length, etc.

Then you generate the insert statement by iterating on the columns

var insertStatement = "INSERT INTO " + tableName + " VALUES( ";
foreach( var column in columns )
    insertStatement += "@" + column.Name + ",";
insertStatement[insertStatement.Length-1] = ')';

var command = new SqlCommand( insertStatement, MsSql );

// iterate over the columns again, but this time set values to the parameters
foreach( var column in columns )
   command.Parameters.AddWithValue( "@"+column.Name, currentRow[column.Name] );