Ruby正則表達式 - 提取單詞

Question

我想從SQL查詢中提取表名。

SELECT col1, col2, count(1) as count_all,     FROM     tbl1, tbl2 where condition order by column

我想要結果["tbl1", "tbl2"]

沒有必要查詢多個表。 在那種情況下，查詢將是

SELECT col1, col2, count(1) as count_all,     FROM     tbl1  where condition order by column

預期結果["tbl1"]

提前致謝！

Answer 1

請注意，這可能會匹配SQL字符串中的內容，因此並不完美。

test = [
"SELECT col1, col2, count(1) as count_all FROM tbl1, tbl2 where condition order by column",
"SELECT col1, col2, count(1) as count_all FROM tbl1 where condition order by column",
"SELECT col1, col2, count(1) as count_all FROM tbl1",
]
tests.map { |str| str.match(/\s*from\s*([a-z_0-9]+(?:,\s*[a-z_0-9]+)*)\b/i); $1 }
#=> ["tbl1, tbl2", "tbl1", "tbl1"]