update readme

sqlfun/readme.md

@@ -2,11 +2,54 @@ This document explains the structure used to document a database function in the
 
 ### funcName
 Name of the function. Function has the same name but has the different arguments syntax will be documented
-in a different file. 
+in the different file. 
 
 funcName can't be null.
 
-### arguments
+### *arguments
+Array of the argument object. This list is empty when a function has no argument.
+
+### argument
+Function argument with below properties.
+
+	#### *arguName
+	argument name. 
+
+	#### *dataTypes
+	dataType of the argument, an argument may has more than one dataType, so this property is array.
+
+	#### description
+	Explanation of this argument.
+
+	#### optional
+	Is this argument optional in the argument list.
+
+### clauses
+SQL clauses used in the function, such as over clause in analytic function.
+
+### *returnType
+return dataType of this function.
+
+### description
+Explanation of this function.
+
+### *targetDBs
+The database version this function is applied to.
+
+### *category
+The category this function belongs to, such as string function.
+
+### ansiCompatible
+Compatible with ANSI SQL.
+
+### package
+The package this function belongs to, usually, it's Oracle plsql function.
+
+### docLink
+The online document for this function.
+
+### sample
+Sample SQL including this function.
 
 ```json
 {

sqlfun/sqlFuncSample.json

@@ -81,15 +81,15 @@
                 "integer",
                 "bigint"
               ],
-              "required": "optional",
+              "optional": true,
               "description": "The number of rows back from the current row from which to obtain a value"
             }
           },
           {
             "argument": {
               "arguName": "default",
               "dataTypes": [],
-              "required": "optional",
+              "optional": true,
               "description": "The value to return when scalar_expression at offset is NULL"
             }
           }

sqlfun/sqlserver/avg.json

@@ -1,7 +1,22 @@
 {
 	"funcName": "AVG",
-	"allDistinct": "optional",
 	"arguments": [
+	  {
+	  	"argument": {
+		  "arguName": "all",
+		  "dataTypes": [],
+		  "optional": true,
+		  "description": "Applies the aggregate function to all values. ALL is the default"
+		}
+	  },
+	  {
+	  	"argument": {
+		  "arguName": "distinct",
+		  "dataTypes": [],
+		  "optional": true,
+		  "description": "Specifies that AVG operates only on one unique instance of each value, regardless of how many times that value occurs"
+		}
+	  },
 	  {
 		"argument": {
 		  "arguName": "expression",

sqlfun/sqlserver/count.json

@@ -0,0 +1,54 @@
+{
+	"funcName": "COUNT",
+	"arguments": [{
+		"argument": {
+			"arguName": "all",
+			"dataTypes": [],
+			"optional": true,
+			"description": "Applies the aggregate function to all values. ALL serves as the default"
+		}
+	},
+	{
+		"argument": {
+			"arguName": "distinct",
+			"dataTypes": [],
+			"optional": true,
+			"description": "Specifies that COUNT returns the number of unique nonnull values"
+		}
+	},
+	{
+		"argument": {
+			"arguName": "expression",
+			"dataTypes": [],
+			"optional": true,
+			"description": "An expression of any type, except image, ntext, or text"
+		}
+	},
+	{
+		"argument": {
+			"arguName": "*",
+			"dataTypes": [],
+			"optional": true,
+			"description": "Specifies that COUNT should count all rows to determine the total table row count to return"
+		}
+	}
+],
+"clauses": [{
+	"clause": {
+		"clauseName": "over",
+		"clauseContent": "[ partition_by_clause ] [order_by_clause] [ ROW_or_RANGE_clause ] ) "
+	}
+}],
+"returnType": "int",
+"description": "This function returns the number of items found in a group",
+"comment": "-- Syntax for SQL Server and Azure SQL Database",
+"targetDBs": ["2008+",
+"Azure SQL Database",
+"Azure SQL Warehouse",
+"Parallel Data Warehouse"],
+"category": "Aggregate",
+"ansiCompatible": "",
+"package": "",
+"docLink": "https://docs.microsoft.com/en-us/sql/t-sql/functions/count-transact-sql?view=sql-server-2017",
+"sample": "SELECT COUNT(DISTINCT Title) FROM HumanResources.Employee;"
+}