I made a quick and dirty plugin to describe my database so that I can send it to the LLM it has 3 commands: SQLDefine SQLTables SQLExecute

db_tools.lua

-- expect a .env file in project root with the following variables:
-- DB_CONNECTION=mysql
-- DB_HOST=db
-- DB_PORT=3306
-- DB_DATABASE=example
-- DB_USERNAME=asdf
-- DB_PASSWORD=asdf

local M = {}

-- Helper function to execute SQL and insert results
local function execute_sql(sql)
  -- Check if .env file exists in project root or current directory
  local env_file = vim.fn.findfile(".env", ".;")
  if env_file == "" then
    print("Error: .env file not found in project hierarchy")
    return nil
  end

  -- Get current line number
  local line_num = vim.fn.line(".")

  -- Insert the SQL command
  vim.api.nvim_buf_set_lines(0, line_num - 1, line_num, false, { sql })

  -- Execute the command and get the output
  local lines = vim.fn.systemlist('source .env && mysql -u $DB_USERNAME -p$DB_PASSWORD -h $DB_HOST -P $DB_PORT $DB_DATABASE -e "' .. sql .. '"')

  -- Filter lines with [Warning]
  lines = vim.tbl_filter(function(line)
    return not line:match("%[Warning%]")
  end, lines)

  -- add a blank line at the end
  table.insert(lines, "")

  -- Insert the filtered lines into the buffer
  vim.api.nvim_buf_set_lines(0, line_num, line_num, false, lines)
end

-- Function to describe a table
local function sql_define()
  -- Get current line content
  local line_content = vim.fn.trim(vim.fn.getline("."))

  -- Check if it's exactly one word
  local words = vim.fn.split(line_content, "\\s\\+")
  if #words ~= 1 then
    print("Error: Current line must contain exactly one word (table name)")
    return
  end

  local table_name = words[1]

  -- Create and execute the SQL command
  execute_sql("DESCRIBE " .. table_name .. ";")
end

-- Function to show all tables in the database
local function sql_tables()
  execute_sql("SHOW TABLES;")
end

-- Function to execute current line or visual selection as SQL
local function sql_execute()
  -- Get current line
  local sql = vim.fn.getline(".")

  -- Trim whitespace
  sql = vim.fn.trim(sql)

  -- Check if empty
  if sql == "" then
    print("Error: No SQL query to execute")
    return
  end

  -- Add semicolon if not present
  if not sql:match(";%s*$") then
    sql = sql .. ";"
  end

  -- Execute the SQL
  execute_sql(sql)
end

function M.setup()
  -- Register commands
  vim.api.nvim_create_user_command("SQLDefine", function()
    sql_define()
  end, { desc = "Describe table from current line and insert results in buffer" })

  vim.api.nvim_create_user_command("SQLTables", function()
    sql_tables()
  end, { desc = "Show all tables in the database" })

  vim.api.nvim_create_user_command("SQLExecute", function()
    sql_execute()
  end, { desc = "Execute current line or visual selection as SQL", range = true })
end

return M