Create first-letter-capitalization-ii.sql

Author: kamyu104

MySQL/first-letter-capitalization-ii.sql

@@ -0,0 +1,74 @@
+# Time:  O(n * l^2 + (n * l) * log(n * l))
+# Space: O(n * l^2)
+
+# recursive cte
+WITH RECURSIVE splitted_word_cte AS (
+    SELECT content_id,
+           content_text,
+           '^' AS delim,
+           CASE
+               WHEN INSTR(content_text, ' ') = 0 AND INSTR(content_text, '-') = 0 THEN
+                   content_text
+               WHEN INSTR(content_text, ' ') != 0 AND INSTR(content_text, '-') = 0 THEN
+                   SUBSTRING(content_text, 1, INSTR(content_text, ' ') - 1)
+               WHEN INSTR(content_text, ' ') = 0 AND INSTR(content_text, '-') != 0 THEN 
+                   SUBSTRING(content_text, 1, INSTR(content_text, '-') - 1)
+               WHEN INSTR(content_text, ' ') != 0 AND INSTR(content_text, '-') != 0 THEN
+                   SUBSTRING(content_text, 1, INSTR(content_text, IF(INSTR(content_text, ' ') < INSTR(content_text, '-'), ' ', '-')) - 1)
+           END AS word,
+           CASE
+               WHEN INSTR(content_text, ' ') = 0 AND INSTR(content_text, '-') = 0 THEN
+                   ''
+               WHEN INSTR(content_text, ' ') != 0 AND INSTR(content_text, '-') = 0 THEN
+                   SUBSTRING(content_text, INSTR(content_text, ' '), 255)
+               WHEN INSTR(content_text, ' ') = 0 AND INSTR(content_text, '-') != 0 THEN
+                   SUBSTRING(content_text, INSTR(content_text, '-'), 255)
+               WHEN INSTR(content_text, ' ') != 0 AND INSTR(content_text, '-') != 0 THEN
+                   SUBSTRING(content_text, INSTR(content_text, IF(INSTR(content_text, ' ') < INSTR(content_text, '-'), ' ', '-')), 255)
+           END AS remain,
+        1 AS idx
+    FROM user_content
+    UNION ALL
+    SELECT 
+        content_id,
+        content_text,
+        SUBSTR(remain, 1, 1) AS delim,
+        CASE
+            WHEN INSTR(SUBSTRING(remain, 2, 255), ' ') = 0 AND INSTR(SUBSTRING(remain, 2, 255), '-') = 0 THEN 
+                SUBSTRING(remain, 2, 255)
+            WHEN INSTR(SUBSTRING(remain, 2, 255), ' ') != 0 AND INSTR(SUBSTRING(remain, 2, 255), '-') = 0 THEN 
+                SUBSTRING(SUBSTRING(remain, 2, 255), 1, INSTR(SUBSTRING(remain, 2, 255), ' ') - 1)
+            WHEN INSTR(SUBSTRING(remain, 2, 255), ' ') = 0 AND INSTR(SUBSTRING(remain, 2, 255), '-') != 0 THEN 
+                SUBSTRING(SUBSTRING(remain, 2, 255), 1, INSTR(SUBSTRING(remain, 2, 255), '-') - 1)
+            WHEN INSTR(SUBSTRING(remain, 2, 255), ' ') != 0 AND INSTR(SUBSTRING(remain, 2, 255), '-') != 0 THEN 
+                SUBSTRING(SUBSTRING(remain, 2, 255), 1, INSTR(SUBSTRING(remain, 2, 255), IF(INSTR(SUBSTRING(remain, 2, 255), ' ') < INSTR(SUBSTRING(remain, 2, 255), '-'), ' ', '-')) - 1)
+        END AS word,
+        CASE
+            WHEN INSTR(SUBSTRING(remain, 2, 255), ' ') = 0 AND INSTR(SUBSTRING(remain, 2, 255), '-') = 0 THEN
+                ''
+            WHEN INSTR(SUBSTRING(remain, 2, 255), ' ') != 0 AND INSTR(SUBSTRING(remain, 2, 255), '-') = 0 THEN 
+                SUBSTRING(SUBSTRING(remain, 2, 255), INSTR(SUBSTRING(remain, 2, 255), ' '), 255)
+            WHEN INSTR(SUBSTRING(remain, 2, 255), ' ') = 0 AND INSTR(SUBSTRING(remain, 2, 255), '-') != 0 THEN 
+                SUBSTRING(SUBSTRING(remain, 2, 255), INSTR(SUBSTRING(remain, 2, 255), '-'), 255)
+            WHEN INSTR(SUBSTRING(remain, 2, 255), ' ') != 0 AND INSTR(SUBSTRING(remain, 2, 255), '-') != 0 THEN 
+                SUBSTRING(SUBSTRING(remain, 2, 255), INSTR(SUBSTRING(remain, 2, 255), IF(INSTR(SUBSTRING(remain, 2, 255), ' ') < INSTR(SUBSTRING(remain, 2, 255), '-'), ' ', '-')), 255)
+        END AS remain,
+        idx + 1
+    FROM splitted_word_cte
+    WHERE remain != ''
+),
+formatted_word_cte AS (
+    SELECT content_id,
+           content_text,
+           idx,
+           word,
+           CONCAT(IF(delim = '^', '', delim), UPPER(SUBSTRING(word, 1, 1)), LOWER(SUBSTRING(word, 2, 255))) AS formatted_word
+    FROM splitted_word_cte
+)
+
+SELECT content_id,
+       content_text AS original_text,
+       GROUP_CONCAT(formatted_word ORDER BY idx SEPARATOR '') AS converted_text
+FROM formatted_word_cte
+GROUP BY 1, 2
+ORDER BY 1;