sql - 检查 Tarantool 中是否存在 SQL 表

Question

如果表已经存在，我如何签入 Tarantool SQL？

Answer 1

仅使用 SQL 工具可以通过以下方式完成：

SELECT EXISTS (select true from "_space" where "name" = 'table_name')

例如：

tarantool> SELECT EXISTS (select true from "_space" where "name" = 'T1')
---
- metadata:
  - name: EXISTS (select true from "_space" where "name" = 'T1')
    type: boolean
  rows:
  - [true]
...

tarantool> SELECT EXISTS (select true from "_space" where "name" = 'T')
---
- metadata:
  - name: EXISTS (select true from "_space" where "name" = 'T')
    type: boolean
  rows:
  - [false]
...

在 Lua 模式下：

tarantool> box.space.T1 ~= nil
---
- true
...

tarantool> box.space.T ~= nil
---
- false
...