owntone-server/src/query.h

#ifndef __query__
#define __query__

typedef enum 
{
    /* node opcodes */
    qot_empty,

    /* conjunctions */
    qot_and,
    qot_or,

    /* negation */
    qot_not,

    /* arithmetic */
    qot_eq,
    qot_ne,
    qot_le,
    qot_lt,
    qot_ge,
    qot_gt,

    /* string */
    qot_is,
    qot_begins,
    qot_ends,
    qot_contains,

    /* constant opcode */
    qot_const,

    /* field types */
    qft_i32,
    qft_i64,
    qft_string

} query_type_t;

typedef struct query_field_ query_field_t;
struct query_field_
{
    query_type_t type;
    const char* name;
    const char* fieldname;
};

typedef struct query_node_ query_node_t;
struct query_node_
{
    query_type_t                type;
    union {
        query_node_t*           node;
        const query_field_t*    field;
        int                     constant;
    }                           left;
    union {
        query_node_t*           node;
        int                     i32;
        long long               i64;
        char*                   str;
    }                           right;
};

extern char *query_build_sql(char *query);

#endif