Make TextFormat case insensitive

Author: Dandandan

src/parser.rs

@@ -1006,7 +1006,7 @@ impl Parser {
         let table_name = self.parse_object_name()?;
         let (columns, constraints) = self.parse_columns()?;
         self.expect_keywords(&[Keyword::STORED, Keyword::AS])?;
-        let file_format = self.parse_identifier()?.value.parse::<FileFormat>()?;
+        let file_format = self.parse_identifier()?.value.to_ascii_uppercase().parse::<FileFormat>()?;
 
         self.expect_keyword(Keyword::LOCATION)?;
         let location = self.parse_literal_string()?;

tests/sqlparser_common.rs

@@ -1289,6 +1289,24 @@ fn parse_create_external_table() {
     }
 }
 
+#[test]
+fn parse_create_external_table_lowercase() {
+    let sql = "create external table uk_cities (\
+               name varchar(100) not null,\
+               lat double null,\
+               lng double)\
+               stored as parquet location '/tmp/example.csv'";
+    let ast = one_statement_parses_to(
+        sql,
+        "CREATE EXTERNAL TABLE uk_cities (\
+         name character varying(100) NOT NULL, \
+         lat double NULL, \
+         lng double) \
+         STORED AS PARQUET LOCATION '/tmp/example.csv'",
+    );
+    assert_matches!(ast, Statement::CreateTable{..});
+}
+
 #[test]
 fn parse_create_table_empty() {
     // Zero-column tables are weird, but supported by at least PostgreSQL.