feat: add IF EXISTS for DROP

[zuston]

For GreptimeTeam/greptimedb#2794

I hereby agree to the terms of the GreptimeDB CLA

What's changed and what's your intention?

• Summarize your change

Add the drop_if_exists to match the mysql statement for drop

• How does this PR work? Need a brief introduction for the changed logic (optional)
• Describe clearly one logical change and avoid lazy messages (optional)
• Describe any limitations of the current code (optional)

Checklist

• I have written the necessary comments.
• I have added the necessary unit tests and integration tests.

Refer to a related PR or issue link (optional)

[zuston]

PTAL @sunng87 @waynexia

[waynexia]

Please run make to generate language-specific code

[zuston]

Please run make to generate language-specific code

Oh yes. I thought the generated code will be did by the bot.

[sunng87]

LGTM.

Can you make a rebase to solve conflicts? Thank you!

[zuston]

LGTM.

Can you make a rebase to solve conflicts? Thank you!

Sorry, it has some conflict and can't rebase. BTW, I don't have complete compile chain like golang and cmake in my mac.

[waynexia]

LGTM.
Can you make a rebase to solve conflicts? Thank you!

Sorry, it has some conflict and can't rebase. BTW, I don't have complete compile chain like golang and cmake in my mac.

Our makefile utilizes docker to generate code, only a docker env is required

[zuston]

LGTM.
Can you make a rebase to solve conflicts? Thank you!

Sorry, it has some conflict and can't rebase. BTW, I don't have complete compile chain like golang and cmake in my mac.

Our makefile utilizes docker to generate code, only a docker env is required

Yes, but my personal mac's docker client is connected to my company's internal docker server due to the limited disk space. And I found the golang dependency is still needed.

[waynexia]

LGTM.
Can you make a rebase to solve conflicts? Thank you!

Sorry, it has some conflict and can't rebase. BTW, I don't have complete compile chain like golang and cmake in my mac.

Our makefile utilizes docker to generate code, only a docker env is required

Yes, but my personal mac's docker client is connected to my company's internal docker server due to the limited disk space. And I found the golang dependency is still needed.

Whoops...