定义table

struct [[eosio::table("sellheros"), eosio::contract("xxx.game")]] sellhero{
        capi_checksum256 tx_hash;
        ....

        auto primary_key() const { return *(uint64_t*)&tx_hash; }
    };

创建table

typedef eosio::multi_index<"sellheros"_n, sellhero> sellhero_tables;

查询

taskhash_tables taskhash_table(_self, account);
auto itr_task = taskhash_table.find(*(uint64_t*)&client_random_hash);
eosio_assert(itr_task != taskhash_table.end(), "random hash is not exist" );

hash 生成

capi_checksum256 bcskill_contract::tx_hash(){
    size_t tx_size = transaction_size();
    char buff[tx_size];
    size_t read = read_transaction(buff, tx_size);
    capi_checksum256 h;
    sha256(buff, read, &h);
    return h;
}

添加数据

capi_checksum256 hash = tx_hash();
    sellhero_tables sellhero_table(_self, _self.value);
    sellhero_table.emplace( _self, [&]( auto& h ) {
        h.tx_hash = hash;
       ...
    });

新增索引方法

using eosio::fixed_bytes;

#define SHA_TO_HASH_FUNC static fixed_bytes<32> checksum256_to_sha256(const capi_checksum256 &hash) \
        { \
            const uint64_t *p64 = reinterpret_cast<const uint64_t *>(&hash); \
            return fixed_bytes<32>::make_from_word_sequence<uint64_t>(p64[0], p64[1], p64[2], p64[3]); \
        }
#define SHA_TO_HASH(hash) checksum256_to_sha256(hash)

struct [[eosio::table, eosio::contract("bcskillsurou")]] tokeninfotb {
        uint64_t id;                                   // id
        capi_checksum256 transaction_id;               // 交易id

        uint64_t primary_key() const { return id; }
        fixed_bytes<32> second_key() const { return SHA_TO_HASH(transaction_id); }
        SHA_TO_HASH_FUNC
        EOSLIB_SERIALIZE(tokeninfotb, (id)(transaction_id))
    };

typedef eosio::multi_index<"tokeninfotb"_n, tokeninfotb, eosio::indexed_by<"bysubkey"_n, eosio::const_mem_fun<tokeninfotb, fixed_bytes<32>, &tokeninfotb::second_key>>> tokeninfo_table;

参考

https://eosio.stackexchange.com/questions/3219/how-to-properly-use-cleos-get-table-with-key-type-sha256-secondary-index-fa