Handle alias when parsing sql(parse_sql_expr)

datafusion-examples/examples/parse_sql_expr.rs

@@ -110,7 +110,7 @@ async fn query_parquet_demo() -> Result<()> {
         .filter(df.parse_sql_expr("int_col < 5 OR double_col = 8.0")?)?
         .aggregate(
             vec![df.parse_sql_expr("double_col")?],
-            vec![df.parse_sql_expr("SUM(int_col) as sum_int_col")?],
+            vec![df.parse_sql_expr("SUM(int_col)")?],
         )?
         // Directly parsing the SQL text into a sort expression is not supported yet, so
         // construct it programmatically

datafusion/core/src/execution/session_state.rs

@@ -69,7 +69,7 @@ use datafusion_sql::planner::{ContextProvider, ParserOptions, PlannerContext, Sq
 use itertools::Itertools;
 use log::{debug, info};
 use object_store::ObjectStore;
-use sqlparser::ast::Expr as SQLExpr;
+use sqlparser::ast::{Expr as SQLExpr, ExprWithAlias as SQLExprWithAlias};
 use sqlparser::dialect::dialect_from_str;
 use std::any::Any;
 use std::collections::hash_map::Entry;
@@ -501,11 +501,22 @@ impl SessionState {
         sql: &str,
         dialect: &str,
     ) -> datafusion_common::Result<SQLExpr> {
+        self.sql_to_expr_with_alias(sql, dialect).map(|x| x.expr)
+    }
+
+    /// parse a sql string into a sqlparser-rs AST [`SQLExprWithAlias`].
+    ///
+    /// See [`Self::create_logical_expr`] for parsing sql to [`Expr`].
+    pub fn sql_to_expr_with_alias(
+        &self,
+        sql: &str,
+        dialect: &str,
+    ) -> datafusion_common::Result<SQLExprWithAlias> {
         let dialect = dialect_from_str(dialect).ok_or_else(|| {
             plan_datafusion_err!(
                 "Unsupported SQL dialect: {dialect}. Available dialects: \
-                     Generic, MySQL, PostgreSQL, Hive, SQLite, Snowflake, Redshift, \
-                     MsSQL, ClickHouse, BigQuery, Ansi."
+                         Generic, MySQL, PostgreSQL, Hive, SQLite, Snowflake, Redshift, \
+                         MsSQL, ClickHouse, BigQuery, Ansi."
             )
         })?;
 
@@ -604,15 +615,15 @@ impl SessionState {
     ) -> datafusion_common::Result<Expr> {
         let dialect = self.config.options().sql_parser.dialect.as_str();
 
-        let sql_expr = self.sql_to_expr(sql, dialect)?;
+        let sql_expr = self.sql_to_expr_with_alias(sql, dialect)?;
 
         let provider = SessionContextProvider {
             state: self,
             tables: HashMap::new(),
         };
 
         let query = SqlToRel::new_with_options(&provider, self.get_parser_options());
-        query.sql_to_expr(sql_expr, df_schema, &mut PlannerContext::new())
+        query.sql_to_expr_with_alias(sql_expr, df_schema, &mut PlannerContext::new())
     }
 
     /// Returns the [`Analyzer`] for this session

datafusion/sql/src/expr/mod.rs

@@ -23,7 +23,8 @@ use datafusion_expr::planner::{
 use recursive::recursive;
 use sqlparser::ast::{
     BinaryOperator, CastFormat, CastKind, DataType as SQLDataType, DictionaryField,
-    Expr as SQLExpr, MapEntry, StructField, Subscript, TrimWhereField, Value,
+    Expr as SQLExpr, ExprWithAlias as SQLExprWithAlias, MapEntry, StructField, Subscript,
+    TrimWhereField, Value,
 };
 
 use datafusion_common::{
@@ -50,6 +51,19 @@ mod unary_op;
 mod value;
 
 impl<'a, S: ContextProvider> SqlToRel<'a, S> {
+    pub(crate) fn sql_expr_to_logical_expr_with_alias(
+        &self,
+        sql: SQLExprWithAlias,
+        schema: &DFSchema,
+        planner_context: &mut PlannerContext,
+    ) -> Result<Expr> {
+        let mut expr =
+            self.sql_expr_to_logical_expr(sql.expr, schema, planner_context)?;
+        if let Some(alias) = sql.alias {
+            expr = expr.alias(alias.value);
+        }
+        Ok(expr)
+    }
     pub(crate) fn sql_expr_to_logical_expr(
         &self,
         sql: SQLExpr,
@@ -131,6 +145,20 @@ impl<'a, S: ContextProvider> SqlToRel<'a, S> {
         )))
     }
 
+    pub fn sql_to_expr_with_alias(
+        &self,
+        sql: SQLExprWithAlias,
+        schema: &DFSchema,
+        planner_context: &mut PlannerContext,
+    ) -> Result<Expr> {
+        let mut expr =
+            self.sql_expr_to_logical_expr_with_alias(sql, schema, planner_context)?;
+        expr = self.rewrite_partial_qualifier(expr, schema);
+        self.validate_schema_satisfies_exprs(schema, &[expr.clone()])?;
+        let (expr, _) = expr.infer_placeholder_types(schema)?;
+        Ok(expr)
+    }
+
     /// Generate a relational expression from a SQL expression
     pub fn sql_to_expr(
         &self,
@@ -1167,4 +1195,25 @@ mod tests {
     test_stack_overflow!(2048);
     test_stack_overflow!(4096);
     test_stack_overflow!(8192);
+    #[test]
+    fn test_sql_to_expr_with_alias() {
+        let schema = DFSchema::empty();
+        let mut planner_context = PlannerContext::default();
+
+        let expr_str = "int_col as int_col_alias";
+
+        let dialect = GenericDialect {};
+        let mut parser = Parser::new(&dialect).try_with_sql(expr_str).unwrap();
+        // from sqlparser
+        let sql_expr = parser.parse_expr_with_alias().unwrap();
+
+        let context_provider = TestContextProvider::new();
+        let sql_to_rel = SqlToRel::new(&context_provider);
+
+        let expr = sql_to_rel
+            .sql_expr_to_logical_expr_with_alias(sql_expr, &schema, &mut planner_context)
+            .unwrap();
+
+        assert!(matches!(expr, Expr::Alias(_)));
+    }
 }

datafusion/sql/src/parser.rs

@@ -20,9 +20,10 @@
 use std::collections::VecDeque;
 use std::fmt;
 
+use sqlparser::ast::ExprWithAlias;
 use sqlparser::{
     ast::{
-        ColumnDef, ColumnOptionDef, Expr, ObjectName, OrderByExpr, Query,
+        ColumnDef, ColumnOptionDef, ObjectName, OrderByExpr, Query,
         Statement as SQLStatement, TableConstraint, Value,
     },
     dialect::{keywords::Keyword, Dialect, GenericDialect},
@@ -328,7 +329,7 @@ impl<'a> DFParser<'a> {
     pub fn parse_sql_into_expr_with_dialect(
         sql: &str,
         dialect: &dyn Dialect,
-    ) -> Result<Expr, ParserError> {
+    ) -> Result<ExprWithAlias, ParserError> {
         let mut parser = DFParser::new_with_dialect(sql, dialect)?;
         parser.parse_expr()
     }
@@ -377,7 +378,7 @@ impl<'a> DFParser<'a> {
         }
     }
 
-    pub fn parse_expr(&mut self) -> Result<Expr, ParserError> {
+    pub fn parse_expr(&mut self) -> Result<ExprWithAlias, ParserError> {
         if let Token::Word(w) = self.parser.peek_token().token {
             match w.keyword {
                 Keyword::CREATE | Keyword::COPY | Keyword::EXPLAIN => {
@@ -387,7 +388,7 @@ impl<'a> DFParser<'a> {
             }
         }
 
-        self.parser.parse_expr()
+        self.parser.parse_expr_with_alias()
     }
 
     /// Parse a SQL `COPY TO` statement