x - a java.io.InputStream object that contains the Parameters: parameterIndex - the first parameter is 1, the second is 2. The byte format of the Unicode stream must be a Java UTF-8, as defined in the
Sqlite insert prepared statement real julianday java driver#
The JDBC driver willĭo any necessary conversion from Unicode to the database char format. Stream as needed until end-of-file is reached.
When a very large Unicode value is input to a LONGVARCHAR Sets the designated parameter to the given input stream, which This method is called on a closed PreparedStatement Marker in the SQL statement if a database access error occurs or x - the Java input stream that contains the ASCII parameter value length - the number of bytes in the stream Throws: SQLException - if parameterIndex does not correspond to a parameter Java stream object or your own subclass that implements the Note: This stream object can either be a standard The JDBC driver willĭo any necessary conversion from ASCII to the database char format. Data will be read from the streamĪs needed until end-of-file is reached. Parameter, it may be more practical to send it via a When a very large ASCII value is input to a LONGVARCHAR Note: I just do a memcpy here, but this would have issues going between big and little endian systems.Sets the designated parameter to the given input stream, which will have The benefits of this technique increase as more fields are converted into larger blobs. That’s only if you don’t need to make queries on the data though. While it’s not advised to just throw everything into a blob and put it in the database, putting data that would be pulled and used together into a binary blob can make sense in some situations.įor example, if you have a point class (x, y, z) with REAL values, it might make sense to store them in a blob rather than three separate fields in row. If you’re not running queries on some of the data, it’s possible to convert it to binary and store it as a blob. Up until now, most of the optimizations have been pretty much the standard advice that you get when looking into bulk insert optimization. They are not only faster on inserts, but across the board for all SQL statements. In all honesty, the documentation for sqlite3_exec should say not to use it at all in favor of prepared statements. Rather than parsing the statement over and over again, the parser only needs to be run once on the statement. Prepared statements are the recommended way of sending queries to SQLite. They can be used to tweak options such as how often the data is flushed to disk of the size of the cache. PRAGMA statements control the behavior of SQLite as a whole.
Nothing will be written to the SQLite database until either END or COMMIT is encountered to signify the transaction should be written and closed. If an error is encountered the ON CONFLICT statement can be used to handle that to your liking. It simply calls sqlite3_exec for each insert in the database.Ī transaction is a way to group SQL statements together. This is the most basic way to insert information into SQLite.
While this article focuses on SQLite some of the techniques shown here will apply to other databases. This will cover the process of optimizing bulk inserts into an SQLite database. SQLite is a light weight database engine that can be easily embedded in applications. Sometimes it’s necessary to get information into a database quickly. The inserts per second graph was obtained by taking the number of inserts and dividing it by the total runtime. Take note that the x axis does not scale linearly, it most closely matches a logarithmic scale. I ran benchmarks to test the performance of each method of inserting data. If that’s necessary, it would be a good idea to serialize the data using a serialization library (ie – protocol buffers or msgpack). Note: I just used memcpy here, but this would have issues going between big and little endian systems. Sqlite3_exec(mDb, "COMMIT TRANSACTION", NULL, NULL, &errorMessage) Sqlite3_bind_blob(stmt, 2, dblBuffer, 24, SQLITE_STATIC)
Sqlite3_exec (mDb, "BEGIN TRANSACTION", NULL, NULL, &errorMessage ) char buffer for ( unsigned i = 0 i < mVal i ++ )
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