MonetDBLite is an embedded SQL database that runs inside another program and does not require the installation of any external software. MonetDBLite is based on free and open-source MonetDB, a product of the Centrum Wiskunde & Informatica.
MonetDBLite is similar in functionality to SQLite, but optimized for analytical (OLAP) use cases.
Installation from source is a matter of typing
make -j
This produces a shared library file libmonetdb5.(so|dll|dylib) in the build/ folder, which contains all required code to run MonetDBLite. This library can then be linked to by your software. On Windows, we use the MinGW-64 toolchains (32 bit, 64 bit (recommended)) and the mingw32-make tool to build the DLL.
See src/embedded/embedded.h for the full API. Here a quick example
#include "embedded.h"
#include <stdio.h>
#define error(msg) {fprintf(stderr, "Failure: %s\n", msg); return -1;}
int main(void) {
char* err = 0;
void* conn = 0;
monetdb_result* result = 0;
size_t r, c;
// first argument is a string for the db directory or NULL for in-memory mode
err = monetdb_startup(NULL, 0, 0);
if (err != 0)
error(err)
conn = monetdb_connect();
if (conn == NULL)
error("Connection failed")
err = monetdb_query(conn, "CREATE TABLE test (x integer, y string)", 1,
NULL, NULL, NULL);
if (err != 0)
error(err)
err = monetdb_query(conn,
"INSERT INTO test VALUES (42, 'Hello'), (NULL, 'World')", 1, NULL,
NULL, NULL);
if (err != 0)
error(err)
err = monetdb_query(conn, "SELECT x, y FROM test; ", 1, &result, NULL,
NULL);
if (err != 0)
error(err)
fprintf(stdout, "Query result with %d cols and %d rows\n", (int) result->ncols,
(int) result->nrows);
for (r = 0; r < result->nrows; r++) {
for (c = 0; c < result->ncols; c++) {
monetdb_column* rcol = monetdb_result_fetch(result, c);
switch (rcol->type) {
case monetdb_int32_t: {
monetdb_column_int32_t * col = (monetdb_column_int32_t *) rcol;
if (col->data[r] == col->null_value) {
printf("NULL");
} else {
printf("%d", (int) col->data[r]);
}
break;
}
case monetdb_str: {
monetdb_column_str * col = (monetdb_column_str *) rcol;
if (col->is_null(col->data[r])) {
printf("NULL");
} else {
printf("%s", (char*) col->data[r]);
}
break;
}
default: {
printf("UNKNOWN");
}
}
if (c + 1 < result->ncols) {
printf(", ");
}
}
printf("\n");
}
monetdb_cleanup_result(conn, result);
monetdb_disconnect(conn);
monetdb_shutdown();
return 0;
}You can build and link this example program with the MonetDBLite shared library (for example) as follows
gcc tests/readme/readme.c -o readme -Isrc/embedded -Lbuild -lmonetdb5
This should produce a binary named readme. Running this binary should produce the following output:
Query result with 2 cols and 2 rows
42, Hello
NULL, World
If you encounter a bug, please file a minimal reproducible example on github. For questions and other discussion, please use stack overflow with the tag monetdblite.