thinking through data structure, please hold

README.md

@@ -1,3 +1,48 @@
 # query-interpreter
 
 Core program to interpret query language strings into structured data, and back again.
+
+## SQL Tokens
+
+We are currently using DataDog's SQL Tokenizer `sqllexer` to scan through SQL strings. 
+Here are the general token types it defines:
+
+```go
+type TokenType int
+
+const (
+ ERROR TokenType = iota
+ EOF
+ SPACE                  // space or newline
+ STRING                 // string literal
+ INCOMPLETE_STRING      // incomplete string literal so that we can obfuscate it, e.g. 'abc
+ NUMBER                 // number literal
+ IDENT                  // identifier
+ QUOTED_IDENT           // quoted identifier
+ OPERATOR               // operator
+ WILDCARD               // wildcard *
+ COMMENT                // comment
+ MULTILINE_COMMENT      // multiline comment
+ PUNCTUATION            // punctuation
+ DOLLAR_QUOTED_FUNCTION // dollar quoted function
+ DOLLAR_QUOTED_STRING   // dollar quoted string
+ POSITIONAL_PARAMETER   // numbered parameter
+ BIND_PARAMETER         // bind parameter
+ FUNCTION               // function
+ SYSTEM_VARIABLE        // system variable
+ UNKNOWN                // unknown token
+ COMMAND                // SQL commands like SELECT, INSERT
+ KEYWORD                // Other SQL keywords
+ JSON_OP                // JSON operators
+ BOOLEAN                // boolean literal
+ NULL                   // null literal
+ PROC_INDICATOR         // procedure indicator
+ CTE_INDICATOR          // CTE indicator
+ ALIAS_INDICATOR        // alias indicator
+)
+
+```
+
+Based on these different token types we will be able to parse out the details of said query into 
+structs to represent them. From those structs we will be able to modify their details any way that 
+we choose and reconstruct them into valid SQL statements.

main.go

@@ -2,82 +2,90 @@ package main
 
 import (
 	"fmt"
+	"strings"
+
 	"github.com/DataDog/go-sqllexer"
 )
 
-type TokenGroupType int
+type QueryType int
 
 const (
-	TOKEN_OTHER   TokenGroupType = iota
-	TOKEN_ACT                    // SELECT, CREATE, etc
-	TOKEN_FILTER                 // WHERE, AND, etc
-	TOKEN_RELATE                 // joins
-	TOKEN_DEFINE                 // column data types, etc
-	TOKEN_CONTROL                // sorting, etc
+	NONE QueryType = iota
+	SELECT
+	UPDATE
+	INSERT
+	DELETE
 )
 
-var tokenGroupMap = map[sqllexer.TokenType]TokenGroupType{
-	sqllexer.ERROR:                  TOKEN_OTHER,
-	sqllexer.EOF:                    TOKEN_OTHER,
-	sqllexer.SPACE:                  TOKEN_OTHER,
-	sqllexer.STRING:                 TOKEN_DEFINE,
-	sqllexer.INCOMPLETE_STRING:      TOKEN_DEFINE,
-	sqllexer.NUMBER:                 TOKEN_DEFINE,
-	sqllexer.IDENT:                  TOKEN_ACT,    // for table/column names
-	sqllexer.QUOTED_IDENT:           TOKEN_RELATE, // for joins
-	sqllexer.OPERATOR:               TOKEN_FILTER,
-	sqllexer.WILDCARD:               TOKEN_ACT,
-	sqllexer.COMMENT:                TOKEN_OTHER,
-	sqllexer.MULTILINE_COMMENT:      TOKEN_OTHER,
-	sqllexer.PUNCTUATION:            TOKEN_OTHER,
-	sqllexer.DOLLAR_QUOTED_FUNCTION: TOKEN_DEFINE,
-	sqllexer.DOLLAR_QUOTED_STRING:   TOKEN_DEFINE,
-	sqllexer.POSITIONAL_PARAMETER:   TOKEN_FILTER,
-	sqllexer.BIND_PARAMETER:         TOKEN_FILTER,
-	sqllexer.FUNCTION:               TOKEN_DEFINE,
-	sqllexer.SYSTEM_VARIABLE:        TOKEN_DEFINE,
-	sqllexer.UNKNOWN:                TOKEN_OTHER,
-	sqllexer.COMMAND:                TOKEN_ACT,
-	sqllexer.KEYWORD:                TOKEN_ACT,
-	sqllexer.JSON_OP:                TOKEN_DEFINE,
-	sqllexer.BOOLEAN:                TOKEN_DEFINE,
-	sqllexer.NULL:                   TOKEN_DEFINE,
-	sqllexer.PROC_INDICATOR:         TOKEN_OTHER,
-	sqllexer.CTE_INDICATOR:          TOKEN_OTHER,
-	sqllexer.ALIAS_INDICATOR:        TOKEN_OTHER,
+type Query struct {
+	Type    QueryType
+	FullSql string
+	IsValid bool
 }
 
-func GetTokenGroupType(tokenType sqllexer.TokenType) (TokenGroupType, bool, bool) {
-	group, exists := tokenGroupMap[tokenType]
-	isStart := false
-	isEnd := false
-
-	if !exists {
-		group = TOKEN_OTHER
-	}
-
-	if group == TOKEN_ACT {
-		isStart = true
-	}
-
-	if tokenType == sqllexer.EOF ||
-		(group == TOKEN_OTHER && tokenType == sqllexer.PUNCTUATION) {
-		isEnd = true
-	}
-
-	return group, isStart, isEnd
+func IsTokenEndOfStatement(token *sqllexer.Token) bool {
+	return (token.Type == sqllexer.EOF || token.Value == ";")
 }
 
-func main() {
-	query := "SELECT * FROM users \n WHERE id = something AND SELECT;"
-	lexer := sqllexer.New(query)
+func GetQueryTypeFromToken(token *sqllexer.Token) QueryType {
+	if token.Type != sqllexer.COMMAND {
+		return NONE
+	}
+
+	var foundType QueryType
+	switch strings.ToUpper(token.Value) {
+	case "SELECT":
+		foundType = SELECT
+	case "UPDATE":
+		foundType = UPDATE
+	case "INSERT":
+		foundType = INSERT
+	case "DELETE":
+		foundType = DELETE
+	default:
+		foundType = NONE
+	}
+
+	return foundType
+}
+
+func IsCrudSqlStatement(token *sqllexer.Token) bool {
+	queryType := GetQueryTypeFromToken(token)
+	return (queryType > 0 && queryType <= 4) // TODO:  Update if QueryTypes Change
+}
+
+func GetQueryTypeFromSql(sql string) QueryType {
+	var queryType QueryType
+
+	lexer := sqllexer.New(sql)
 	for {
 		token := lexer.Scan()
-		tokenGroup, isStart, isEnd := GetTokenGroupType(token.Type)
-		fmt.Println(token.Value, token.Type, tokenGroup, isStart, isEnd)
+		if IsTokenEndOfStatement(token) {
+			break
+		}
 
-		if token.Type == sqllexer.EOF {
+		queryType = GetQueryTypeFromToken(token)
+		if queryType > 0 {
 			break
 		}
 	}
+
+	return queryType
+}
+
+func main() {
+	query := "DELETE * FROM users \n WHERE id = something AND SELECT;"
+	newQuery := GetQueryTypeFromSql(query)
+
+	fmt.Println(newQuery)
+
+	//lexer := sqllexer.New(query)
+	//for {
+	//	token := lexer.Scan()
+	//	fmt.Println(token.Value, token.Type)
+
+	//	if token.Type == sqllexer.EOF {
+	//		break
+	//	}
+	//}
 }