2022-07-20

1. postgresql 判断表是否存在,存在则删除

/* 判断后删除表 */
DO
$do$
BEGIN
if( (select 1 from pg_tables
    where schemaname = 'public' and tablename = 'CraftCategory') 
is not null ) then
    DROP TABLE "CraftCategory";
end if;

if( (select 1 from pg_tables
    where schemaname = 'public' and tablename = 'CraftEntity') 
is not null ) then
    DROP TABLE "CraftEntity";
end if;

END
$do$

2. 更新rust工具
   Rust 由工具 rustup 安装和管理

rustup update
// 查看cargo 版本
cargo --version

3. rust换源
   参考:https://course.rs/first-try/slowly-downloading.html
   在 $HOME/.cargo/config.toml 添加以下内容

# 选择的镜像源
# 喜欢哪个用哪个吧，没有注释掉的那个就是你选择的
#replace-with = 'ustc'
#replace-with = 'tuna'
#replace-with = 'sjtu'
#replace-with = 'rustcc'
replace-with = 'aliyun'

# 源码地址
[source.crates-io]
registry = "https://github.com/rust-lang/crates.io-index"


# 镜像地址

# 清华大学
[source.tuna]
registry = "https://mirrors.tuna.tsinghua.edu.cn/git/crates.io-index.git"

# 中国科学技术大学
[source.ustc]
registry = "git://mirrors.ustc.edu.cn/crates.io-index"

# 上海交通大学
[source.sjtu]
registry = "https://mirrors.sjtug.sjtu.edu.cn/git/crates.io-index"

# rustcc社区
[source.rustcc]
registry = "git://crates.rustcc.cn/crates.io-index"

# 阿里云
[source.aliyun]
registry = "https://code.aliyun.com/rustcc/crates.io-index"