External SQL/YQL files

You may generate SQL queries or YQL queries (for YDB) from external .sql/.yql files. To do this, call the following cmake function in your CMakeLists.txt:

userver_add_sql_library(
    ${PROJECT_NAME}_sql
    NAMESPACE samples_postgres_service
    OUTPUT_DIR ${CMAKE_CURRENT_BINARY_DIR}
    SQL_FILES *.sql
)
target_link_libraries(${PROJECT_NAME} ${PROJECT_NAME}_sql)

It will generate the .hpp file with following variable:

extern const USERVER_NAMESPACE::storages::Query kCreateTable;

And the definition in .cpp looks something like that:

const USERVER_NAMESPACE::storages::Query kCreateTable = {
    R"-(
    CREATE TABLE IF NOT EXISTS key_value_table (
            key VARCHAR PRIMARY KEY,
            value VARCHAR
    )
    )-",
    USERVER_NAMESPACE::storages::Query::Name("create_table"),
    USERVER_NAMESPACE::storages::Query::LogMode::kFull,
};

You may use it as usual by passing to storages::postgres::Cluster::Execute() for SQL files or ydb::TableClient::ExecuteDataQuery() for YQL files.