SQLite to Oracle - database

Question

I have a SQLite database in one system, I need to extract the data stored in SQLite to Oracle database. How do I do this?

Answer 1

Oracle provides product called the Oracle Database Mobile Server (previously called Oracle Database Lite) which allows you to synchronize between a SQLite and an Oracle database. It provides scalable bi-directional sync, schema mapping, security, etc. The Mobile Server supports both synchronous and asynchronous data sync. If this is more than a one-time export and you need to keep your SQLite and Oracle Databases in sync, this is a great tool!
Disclaimer: I'm one of the Product Managers for Oracle Database Mobile Server, so I'm a bit biased. However, the Mobile Server really is a great tool to use for keeping your SQLite (or Berkeley DB) and Oracle Databases in sync.

Answer 2

You'll have to convert the SQLite to a text file (not certain of the format) and then use Oracle to load the database from text (source is http://www.orafaq.com/wiki/SQLite). You can use the .dump command from the SQLite interactive shell to dump to a text file (see the docs for syntax).

Answer 3

SQL Loader is a utility that will read a delimited text file and import it into an oracle database. You will need to map out how each column from your flat file out of sqlite matches to the corresponding one in the Oracle database. Here is a good FAQ that should help you get started.

Answer 4

If you are a developer, you could develop an application to perform the sync. You would do
SELECT name FROM sqlite_master WHERE type='table'
to get the table names, then you could re-create them in Oracle (you can do DROP TABLE tablename in Oracle first, to avoid a conflict, assuming SQLite will be authoritative) with CREATE TABLE commands. Getting the columns for each one takes
SELECT sql FROM sqlite_master WHERE type='table' and name='MyTable'
And then you have to parse the result:
string columnNames = sql.replace(/^[^\(]+\(([^\)]+)\)/g, '$1').replace(/ [^,]+/g, '').split(',');
string[] columnArray = columnNames.Split(',');
foreach (string s in columnArray)
{
// Add column to table using:
// ALTER TABLE MyTable ADD COLUMN s NVARCHAR(250)
}
A StringBuilder can be used to collect the table name with its columns to create your INSERT command. To add the values, it would just be a matter of doing SELECT * FROM MyTable for each of the tables during your loop through the table names you got back from the initial query. You would iterate the columns of the rows of the datatable you were returned and add the values to the StringBuilder:
INSERT INTO MyTable ( + columnA, columnB, etc. + ) VALUES ( datarow[0], datarow[1], etc. + ).
Not exactly like that, though - you fill in the data by appending the column name and its data as you run through the loops. You can get the column names by appending s in that foreach loop, above. Each column value is then set using a foreach loop that gives you each object obj in drData.ItemArray. If all you have are string fields, it's easy, you just add obj.ToString() to your StringBuilder for each column value in your query like I have below. Then you run the query after collecting all of the column values for each row. You use a new StringBuilder for each row - it needs to get reset to INSERT INTO MyTable ( + columnA, columnB, etc. + ) VALUES ( prior to each new row, so the new column values can be appended.
If you have mixed datatypes (i.e. DATE, BLOB, etc.), you'll need to determine the column types along the way, store it in a list or array, then use a counter to determine the index of that list/array slot and get the type, so you know how to translate your object into something Oracle can use - whether that means simply adding to_date() to the result, with formatting, for a date (since SQLite stores these as date strings with the format yyyy-MM-dd HH:mm:ss), or adding it to an OracleParameter for a BLOB and sending that along to a RunOracleCommand function. (I did not go into this, below.)
Putting all of this together yields this:
string[] columnArray = null;
DataTable dtTableNames = GetSQLiteTable("SELECT name FROM sqlite_master WHERE type='table'");
if (dtTableNames != null && dtTableNames.Rows != null)
{
if (dtTableNames.Rows.Count > 0)
{
// We have tables
foreach (DataRow dr in dtTableNames.Rows)
{
// Do everything about this table here
StringBuilder sb = new StringBuilder();
sb.Append("INSERT INTO " + tableName + " ("); // we will collect column names here
string tableName = dr["NAME"] != null ? dr["NAME"].ToString() : String.Empty;
if (!String.IsNullOrEmpty(tableName))
{
RunOracleCommand("DROP TABLE " + tableName);
RunOracleCommand("CREATE TABLE " + tableName);
}
DataTable dtColumnNames = GetSQLiteTable("SELECT sql FROM sqlite_master WHERE type='table' AND name='"+tableName+"'");
if (dtColumnNames != null && dtColumnNames.Rows != null)
{
if (dtColumnNames.Rows.Count > 0)
{
// We have columns
foreach (DataRow drCol in dtTableNames.Rows)
{
string sql = drCol["SQL"] != null ? drCol["SQL"].ToString() : String.Empty;
if (!String.IsNullOrEmpty(sql))
{
string columnNames = sql.replace(/^[^\(]+\(([^\)]+)\)/g, '$1').replace(/ [^,]+/g, '').split(',');
columnArray = columnNames.Split(',');
foreach (string s in columnArray)
{
// Add column to table using:
RunOracleCommand("ALTER TABLE " + tableName + " ADD COLUMN " + s + " NVARCHAR(250)"); // can hard-code like this or use logic to determine the datatype/column width
sb.Append("'" + s + "',");
}
sb.TrimEnd(",");
sb.Append(") VALUES (");
}
}
}
}
// Get SQLite Table data for insertion to Oracle
DataTable dtTableData = GetSQLiteTable("SELECT * FROM " + tableName);
if (dtTableData != null && dtTableData.Rows != null)
{
if (dtTableData.Rows.Count > 0)
{
// We have data
foreach (DataRow drData in dtTableData.Rows)
{
StringBuilder sbRow = sb; // resets to baseline for each row
foreach (object obj in drData.ItemArray)
{
// This is simplistic and assumes you have string data for an NVARCHAR field
sbRow.Append("'" + obj.ToString() + "',");
}
sbRow.TrimEnd(",");
sbRow.Append(")");
RunOracleCommand(sbRow.ToString());
}
}
}
}
}
}
All of this assumes you have a RunOracleCommand() void function that can take a SQL command and run it against an Oracle DB, and a GetSQLiteTable() function that can return a DataTable from your SQLite DB by passing it a SQL command.
Note that this code is untested, as I wrote it directly in this post, but it is based heavily on code I wrote to sync Oracle into SQLite, which has been tested and works.