fix errors

Author: huaxingao

docs/sql-ref-syntax-ddl-create-database.md

@@ -40,7 +40,7 @@ CREATE { DATABASE | SCHEMA } [ IF NOT EXISTS ] database_name
 
 * **IF NOT EXISTS**
 
-    Creates a database with the given name if it doesn't exists. If a database with the same name already exists, nothing will happen.
+    Creates a database with the given name if it does not exist. If a database with the same name already exists, nothing will happen.
 
 * **database_directory**
 

docs/sql-ref-syntax-ddl-create-table-hiveformat.md

@@ -63,7 +63,7 @@ as any order. For example, you can write COMMENT table_comment after TBLPROPERTI
 
 * **STORED AS**
 
-    File format for table storage, could be TEXTFILE, ORC, PARQUET,etc.
+    File format for table storage, could be TEXTFILE, ORC, PARQUET, etc.
 
 * **LOCATION**
 

docs/sql-ref-syntax-ddl-create-table-like.md

@@ -52,7 +52,7 @@ CREATE TABLE [IF NOT EXISTS] table_identifier LIKE source_table_identifier
 
 * **STORED AS**
 
-    File format for table storage, could be TEXTFILE, ORC, PARQUET,etc.
+    File format for table storage, could be TEXTFILE, ORC, PARQUET, etc.
 
 * **TBLPROPERTIES**
 

docs/sql-ref-syntax-ddl-create-view.md

@@ -46,7 +46,7 @@ CREATE [ OR REPLACE ] [ [ GLOBAL ] TEMPORARY ] VIEW [ IF NOT EXISTS ] view_ident
 
 * **IF NOT EXISTS**
 
-    Creates a view if it does not exists.
+    Creates a view if it does not exist.
 
 * **view_identifier**
 

docs/sql-ref-syntax-ddl-drop-table.md

@@ -36,7 +36,7 @@ DROP TABLE [ IF EXISTS ] table_identifier
 
 * **IF EXISTS**
 
-    If specified, no exception is thrown when the table does not exists.
+    If specified, no exception is thrown when the table does not exist.
 
 * **table_identifier**
 
@@ -53,13 +53,13 @@ DROP TABLE employeetable;
 -- Assumes a table named `employeetable` exists in the `userdb` database
 DROP TABLE userdb.employeetable;
 
--- Assumes a table named `employeetable` does not exists.
+-- Assumes a table named `employeetable` does not exist.
 -- Throws exception
 DROP TABLE employeetable;
 Error: org.apache.spark.sql.AnalysisException: Table or view not found: employeetable;
 (state=,code=0)
 
--- Assumes a table named `employeetable` does not exists,Try with IF EXISTS
+-- Assumes a table named `employeetable` does not exist,Try with IF EXISTS
 -- this time it will not throw exception
 DROP TABLE IF EXISTS employeetable;
 ```

docs/sql-ref-syntax-ddl-drop-view.md

@@ -33,7 +33,7 @@ DROP VIEW [ IF EXISTS ] view_identifier
 
 * **IF EXISTS**
 
-    If specified, no exception is thrown when the view does not exists.
+    If specified, no exception is thrown when the view does not exist.
 
 * **view_identifier**
 
@@ -50,13 +50,13 @@ DROP VIEW employeeView;
 -- Assumes a view named `employeeView` exists in the `userdb` database
 DROP VIEW userdb.employeeView;
 
--- Assumes a view named `employeeView` does not exists.
+-- Assumes a view named `employeeView` does not exist.
 -- Throws exception
 DROP VIEW employeeView;
 Error: org.apache.spark.sql.AnalysisException: Table or view not found: employeeView;
 (state=,code=0)
 
--- Assumes a view named `employeeView` does not exists,Try with IF EXISTS
+-- Assumes a view named `employeeView` does not exist,Try with IF EXISTS
 -- this time it will not throw exception
 DROP VIEW IF EXISTS employeeView;
 ```