From b690640ca6872db15bb5d842bb1f11fefc675b65 Mon Sep 17 00:00:00 2001
From: joe-re <joe.tialtngo@gmail.com>
Date: Sun, 16 Aug 2020 11:26:38 +0000
Subject: [PATCH] deal with subquery in where clause

---
 packages/sql-parser/base/fromClauseParser.js |  5 ++++-
 packages/sql-parser/base/parser.js           |  5 ++++-
 packages/sql-parser/parser.pegjs             |  1 +
 packages/sql-parser/test/subquery.test.js    | 16 ++++++++++++++++
 4 files changed, 25 insertions(+), 2 deletions(-)
 create mode 100644 packages/sql-parser/test/subquery.test.js

diff --git a/packages/sql-parser/base/fromClauseParser.js b/packages/sql-parser/base/fromClauseParser.js
index 26b8931d..34122fc8 100644
--- a/packages/sql-parser/base/fromClauseParser.js
+++ b/packages/sql-parser/base/fromClauseParser.js
@@ -5049,7 +5049,10 @@ function peg$parse(input, options) {
                 s0 = peg$FAILED;
               }
               if (s0 === peg$FAILED) {
-                s0 = peg$parsevar_decl();
+                s0 = peg$parseselect_stmt();
+                if (s0 === peg$FAILED) {
+                  s0 = peg$parsevar_decl();
+                }
               }
             }
           }
diff --git a/packages/sql-parser/base/parser.js b/packages/sql-parser/base/parser.js
index 82d899ee..b02164b8 100644
--- a/packages/sql-parser/base/parser.js
+++ b/packages/sql-parser/base/parser.js
@@ -5049,7 +5049,10 @@ function peg$parse(input, options) {
                 s0 = peg$FAILED;
               }
               if (s0 === peg$FAILED) {
-                s0 = peg$parsevar_decl();
+                s0 = peg$parseselect_stmt();
+                if (s0 === peg$FAILED) {
+                  s0 = peg$parsevar_decl();
+                }
               }
             }
           }
diff --git a/packages/sql-parser/parser.pegjs b/packages/sql-parser/parser.pegjs
index bf8fb813..396f6921 100644
--- a/packages/sql-parser/parser.pegjs
+++ b/packages/sql-parser/parser.pegjs
@@ -752,6 +752,7 @@ primary
       e.paren = true; 
       return e; 
     } 
+  / select_stmt
   / var_decl
 
 column_ref 
diff --git a/packages/sql-parser/test/subquery.test.js b/packages/sql-parser/test/subquery.test.js
new file mode 100644
index 00000000..2a4afff4
--- /dev/null
+++ b/packages/sql-parser/test/subquery.test.js
@@ -0,0 +1,16 @@
+const { parse } = require('../index')
+
+describe('Subquery in where clause', () => {
+ it('should success to parse', () => {
+    const sql = `
+      SELECT *
+      FROM T1
+      WHERE T1.num = (SELECT max(T2.num) from T2)
+    `
+     const result = parse(sql)
+     expect(result).toBeDefined()
+     expect(result).toMatchObject({ type: 'select' })
+     expect(result.where.expression.left).toMatchObject({ type: 'column_ref' })
+     expect(result.where.expression.right).toMatchObject({ type: 'select' })
+  })
+})
\ No newline at end of file