Welcome to the community of bindings contributors! chDB offers a Stable C ABI, which facilitates the development of bindings in various languages. For a C language calling demo, please refer to the examples in the /examples directory, such as chdbDlopen.c, chdbSimple.c, and chdbStub.c.

Here is a table outlining the current status of language bindings for chDB:

chDB provides several stable ABIs for other language bindings.

The following is the definition of the local_result and local_result_v2 structure:

struct local_result
{
    char * buf;
    size_t len;
    void * _vec; // std::vector<char> *, for freeing
    double elapsed;
    uint64_t rows_read;
    uint64_t bytes_read;
};

struct local_result_v2
{
    char * buf;
    size_t len;
    void * _vec; // std::vector<char> *, for freeing
    double elapsed;
    uint64_t rows_read;
    uint64_t bytes_read;
    char * error_message;
};

The following is the definition of the query_stable, free_result and query_stable_v2, free_result_v2 functions.

// v1 API
struct local_result * query_stable(int argc, char ** argv);
void free_result(struct local_result * result);

// v2 API added `char * error_message`.
struct local_result_v2 * query_stable_v2(int argc, char ** argv);
void free_result_v2(struct local_result_v2 * result);

query_stable and query_stable_v2 accept the same parameters just like the clickhouse-local command line tool. You can check queryToBuffer function in LocalChdb.cpp as an example.

The difference is that query_stable_v2 adds the char * error_message field. You can check if the error_message field is NULL to determine if an error occurred.

free_result and free_result_v2 are used to free the local_result and local_result_v2 memory. For GC languages, you can call free_result or free_result_v2 in the destructor of the object.

• By chDB v1.2.0, the `query_stable_v2`` returns nil if the query(eg. CREATE TABLE) successes but returns no data. We will change this behavior in the future.

If you have already developed bindings for a language not listed above,

If you are interested in contributing to the development of bindings for a language not listed above, please contact us at:

• Discord: bindings
• Email: auxten@clickhouse.com
• Twitter: @chdb