支持in 普通语法 和子查询的sqlc https://github.com/xiazemin/sqlc

localhost:sqlc xiazemin$ ln -s ../sqlc_study/query/ . localhost:sqlc xiazemin$ ln -s ../sqlc_study/schema/ . localhost:sqlc xiazemin$ ln -s ../sqlc_study/sqlc.yaml/ .

mysql> insert into company (id,name) values (0,"a"); mysql> insert into company (id,name) values (1,"a"); mysql> insert into authors (id,name,bio,company_id) values(15,'Brian','Brian',1);

~/go/bin/sqlc generate

生成Interface emit_interface: true

生成mock go generate ./...

参考： https://segmentfault.com/a/1190000022529075?utm_source=tag-newest

mysql> select * from authors; +----+-----------------+-------------------------------------------------------------------------+------------+------+-----------+-------------+-------+--------------+ | id | name | bio | company_id | size | empty_col | default_col | size1 | default_col1 | +----+-----------------+-------------------------------------------------------------------------+------------+------+-----------+-------------+-------+--------------+ | 1 | a | a | 1 | 1 | NULL | 0 | NULL | 1 | | 2 | b | b | 2 | NULL | NULL | 0 | NULL | 0 | | 10 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 11 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 12 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 13 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 14 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 15 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 16 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 17 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 18 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 19 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 20 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 21 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | | 22 | Brian Kernighan | Co-author of The C Programming Language and The Go Programming Language | 1 | NULL | NULL | 0 | NULL | 0 | +----+-----------------+-------------------------------------------------------------------------+------------+------+-----------+-------------+-------+--------------+

使用聚合函数的情况下

如果NOT NULL，没有命中会返回 NULL ,且走了索引才会，in 不会 命中了 返回默认值 如果DEFAULT NULL，但是没有插入数据，且没有命中会返回NULL 用了sql.null不会报错 命中了 返回NULL 如果插入数据了，没有命中会返回NULL 命中了 返回NULL

mysql> select max(default_col) from authors where id=11234567890; +------------------+ | max(default_col) | +------------------+ | NULL | +------------------+ 1 row in set (0.00 sec)

mysql> select max(default_col) from authors where id=1; +------------------+ | max(default_col) | +------------------+ | 0 | +------------------+ 1 row in set (0.00 sec)

mysql> select max(empty_col) from authors where id=11234567890; +----------------+ | max(empty_col) | +----------------+ | NULL | +----------------+ 1 row in set (0.00 sec)

mysql> select max(empty_col) from authors where id=1; +----------------+ | max(empty_col) | +----------------+ | NULL | +----------------+ 1 row in set (0.00 sec)

/** mysql> select empty_col from authors where id=1; +-----------+ | empty_col | +-----------+ | NULL | +-----------+ 1 row in set (0.01 sec)

mysql> select empty_col from authors where id=11234567890; Empty set (0.00 sec)

mysql> select default_col from authors where id=1; +-------------+ | default_col | +-------------+ | 0 | +-------------+ 1 row in set (0.00 sec)

mysql> select default_col from authors where id=11234567890; Empty set (0.00 sec)

mysql> */

GetMax_default_col 0 sql: Scan error on column index 0, name "max(default_col)": converting NULL to int32 is unsupported 2021/06/11 18:33:26 CreateAuthor error:Error 1364: Field 'default_col' doesn't have a default value