Inserting rows in sql table problem, some columns inserted NULL value

I have 2 DB with multiple tables. All tables have the same syntax. Here I have a method that takes name of the table as an argument. The table that I try to insert is with 3 columns (int, varchar, int). The problem is, only the first row is inserted, and the 2 and 3 row is NULL, I don't know what is the problem. Any suggestions, please?

public void getAndInsertData(String nameOfTable) {
try {
Class.forName("com.mysql.jdbc.Driver");
Connection con1 = DriverManager.getConnection(urlDB1, user1, password1);
Statement s1 = con1.createStatement();
Connection con2 = DriverManager.getConnection(urlDB2, user2, password2);
Statement s2 = con2.createStatement();
ResultSet rs1 = s1.executeQuery("SELECT * FROM " + nameOfTable);
ResultSetMetaData rsmd1 = rs1.getMetaData();
int columnCount = rsmd1.getColumnCount();
for (int column = 1; column <= columnCount; column++) {
String columnName = rsmd1.getColumnName(column);
int columnType = rsmd1.getColumnType(column);
while (rs1.next()) {
switch (columnType) {
case Types.INTEGER:
case Types.SMALLINT:
case Types.BIGINT:
case Types.TINYINT:
int integerValue = rs1.getInt(column);
String integerQuery = "insert into " + nameOfTable + " (" + columnName + ") VALUES("
+ integerValue + ");";
s2.executeUpdate(integerQuery);
break;
case Types.VARCHAR:
case Types.NVARCHAR:
case Types.LONGNVARCHAR:
case Types.LONGVARCHAR:
String varcharValue = rs1.getString(column);
String varcharQuery = "insert into " + nameOfTable + " (" + columnName + ") VALUES("
+ varcharValue + ");";
s2.executeUpdate(varcharQuery);
default:
System.out.println("Default");
break;
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
}

Your integerQuery and varcharQuery both insert into datebase table a record with one filled column and blank other columns. Because you provide value to one column only.

As The Impaler already mentioned, your loops are at the wrong place.
For every record of rs1, you want to insert one record using s2.

You can build a prepared statement first using the metadata and then inject the values:
ResultSetMetaData rsmd1 = rs1.getMetaData();
int columnCount = rsmd1.getColumnCount();

StringBuffer sql=new StringBuffer("insert into "+nameOfTable+" (");
for (int column = 1; column <= columnCount; column++) {
String columnName = rsmd1.getColumnName(column);
if(column>1)
sql.append(",");
sql.append(columnName);
}
sql.append(") values (");
for(int i=1;i<=columnCount;i++)
{
sql.append((i==1?"":",")+ "?");
}
sql.append(")");
System.out.println("Prepared SQL:"+sql.toString());
// sql = insert into nameOfTable (col1,col2,col3) values (?,?,?)
PreparedStatement s2= con2.prepareStatement(sql.toString());
while (rs1.next()) {
s2.clearParameters();
for (int column = 1; column <= columnCount; column++) {
int columnType = rsmd1.getColumnType(column);
switch (columnType) {
case Types.INTEGER:
case Types.SMALLINT:
case Types.BIGINT:
case Types.TINYINT:
s2.setInt(column, rs1.getInt(column));
break;
case Types.VARCHAR:
case Types.NVARCHAR:
case Types.LONGNVARCHAR:
case Types.LONGVARCHAR:
s2.setString(column, rs1.getString(column));
break;
default:
System.err.println("Not supported type for column "+column+" with type:"+columnType);
s2.setNull(column, columnType);
break;
}
} // end of for loop
// execute statement once per record in rs1
s2.executeUpdate();
} // end of while

A few issues:

• Use try-with-resources to make sure the JDBC resources are cleaned up correctly.

• No need for a switch statement, because we don't actually need to know the types of the columns. The JDBC driver will handle that if you use getObject() and setObject().

• Only execute one INSERT per row from the source table.

• Use batching when inserting a lot of records, for better performance.

Here is how to do it:

try (
Connection conSource = DriverManager.getConnection(urlDB1, user1, password1);
Connection conTarget = DriverManager.getConnection(urlDB2, user2, password2);
Statement stmtSource = conSource.createStatement();
ResultSet rsSource = stmtSource.executeQuery("SELECT * FROM " + nameOfTable);
) {
// Build insert statement
ResultSetMetaData metaData = rsSource.getMetaData();
int columnCount = metaData.getColumnCount();
StringBuilder sql = new StringBuilder("INSERT INTO " + nameOfTable + " (");
for (int column = 1; column <= columnCount; column++) {
if (column != 1)
sql.append(", ");
sql.append(metaData.getColumnName(column));
}
sql.append(") VALUES (");
for (int column = 1; column <= columnCount; column++) {
if (column != 1)
sql.append(", ");
sql.append("?");
}
sql.append(")");
// Copy data
conTarget.setAutoCommit(false);
try (PreparedStatement stmtTarget = conTarget.prepareStatement(sql.toString())) {
int batchSize = 0;
while (rsSource.next()) {
for (int column = 1; column <= columnCount; column++) {
// Copy row here. Use switch statement to control the mapping
// if source and target table columns don't have compatible types.
// The following statement should work for most types, so switch
// statement only needs to cover the exceptions.
stmtTarget.setObject(column, rsSource.getObject(column), metaData.getColumnType(column));
}
stmtTarget.addBatch();
if (++batchSize == 1000) { // Flush every 1000 rows to prevent memory overflow
stmtTarget.executeBatch();
batchSize = 0;
}
}
if (batchSize != 0)
stmtTarget.executeBatch();
}
conTarget.commit();
}