SGA-3801 Added support for concatenating string literals saperated by space in mySQL

Author: etgarperets

src/dialect/mod.rs

@@ -476,6 +476,12 @@ pub trait Dialect: Debug + Any {
         false
     }
 
+    // Does the Dialect support concatenating of string literal
+    // Example: SELECT 'Hello ' "world" => SELECT 'Hello world'
+    fn supports_concat_quoted_identifiers(&self) -> bool {
+        false
+    }
+
     /// Does the dialect support trailing commas in the projection list?
     fn supports_projection_trailing_commas(&self) -> bool {
         self.supports_trailing_commas()

src/dialect/mysql.rs

@@ -71,6 +71,11 @@ impl Dialect for MySqlDialect {
         true
     }
 
+    // see <https://dev.mysql.com/doc/refman/8.4/en/string-functions.html#:~:text=mysql%3E%20SELECT%20%27My%27%20%27S%27%20%27QL%27%3B%0A%20%20%20%20%20%20%20%20%2D%3E%20%27MySQL%27>
+    fn supports_concat_quoted_identifiers(&self) -> bool {
+        true
+    }
+
     fn ignores_wildcard_escapes(&self) -> bool {
         true
     }

src/parser/mod.rs

@@ -9808,8 +9808,18 @@ impl<'a> Parser<'a> {
             // bigdecimal feature is enabled, and is otherwise a no-op
             // (i.e., it returns the input string).
             Token::Number(n, l) => ok_value(Value::Number(Self::parse(n, span.start)?, l)),
-            Token::SingleQuotedString(ref s) => ok_value(Value::SingleQuotedString(s.to_string())),
-            Token::DoubleQuotedString(ref s) => ok_value(Value::DoubleQuotedString(s.to_string())),
+            Token::SingleQuotedString(ref s) => {
+                if self.dialect.supports_concat_quoted_identifiers() {
+                    return ok_value(Value::SingleQuotedString(self.combine_quoted(next_token)));
+                }
+                ok_value(Value::SingleQuotedString(s.to_string()))
+            }
+            Token::DoubleQuotedString(ref s) => {
+                if self.dialect.supports_concat_quoted_identifiers() {
+                    return ok_value(Value::DoubleQuotedString(self.combine_quoted(next_token)));
+                }
+                ok_value(Value::DoubleQuotedString(s.to_string()))
+            }
             Token::TripleSingleQuotedString(ref s) => {
                 ok_value(Value::TripleSingleQuotedString(s.to_string()))
             }
@@ -9879,6 +9889,35 @@ impl<'a> Parser<'a> {
         }
     }
 
+    fn is_quoted_string(&self, token: &Token) -> bool {
+        matches!(
+            token,
+            Token::SingleQuotedString(_) | Token::DoubleQuotedString(_)
+        )
+    }
+
+    fn get_quoted_string(&self, token: &Token) -> String {
+        match token {
+            Token::SingleQuotedString(s) => s.clone(),
+            Token::DoubleQuotedString(s) => s.clone(),
+            _ => String::new(),
+        }
+    }
+
+    fn combine_quoted(&mut self, token: TokenWithSpan) -> String {
+        let mut combined_string = self.get_quoted_string(&token.token);
+        loop {
+            let next_token = self.next_token();
+            if !self.is_quoted_string(&next_token.token) {
+                self.prev_token();
+                break;
+            }
+            let s = self.get_quoted_string(&next_token.token);
+            combined_string.push_str(&s);
+        }
+        combined_string
+    }
+
     /// Parse an unsigned numeric literal
     pub fn parse_number_value(&mut self) -> Result<ValueWithSpan, ParserError> {
         let value_wrapper = self.parse_value()?;

tests/sqlparser_mysql.rs

@@ -4247,3 +4247,12 @@ fn test_create_index_options() {
         "CREATE INDEX idx_name ON t(c1, c2) USING BTREE LOCK = EXCLUSIVE ALGORITHM = DEFAULT",
     );
 }
+
+#[test]
+fn parse_adjacent_string_literal_concatenation() {
+    let sql = r#"SELECT 'M' "y" 'S' "q" 'l'"#;
+    mysql().one_statement_parses_to(sql, r"SELECT 'MySql'");
+
+    let sql = "SELECT * FROM t WHERE col = 'Hello' \n ' ' \t 'World!'";
+    mysql().one_statement_parses_to(sql, r"SELECT * FROM t WHERE col = 'Hello World!'");
+}