basic SQL functions

atom

@@ -229,6 +229,190 @@ closeDatabase() {
 	rm "$tempdir"/sqlite.{in,out}
 }
 
+Select() {
+#Select table [col1 [col2 [..]]] <	WHERE_key WHERE_value
+#					[WHERE_key WHERE_value
+#					[…]]
+	local			\
+		table="$1"	\
+		col		\
+		columns		\
+		results		\
+		where_statement
+	shift
+	for col
+	do
+		(( ${#columns} )) && columns+=','
+		columns+="$col"
+	done
+	while read key value
+	do
+		(( ${#where_statement} )) && where_statement+=( "AND" )
+		if [[ $value == NULL ]]
+		then
+			where_statement+=( "$key is NULL" )
+		else
+			where_statement+=( "$key='$value'" )
+		fi
+	done
+	echo	"SELECT IFNULL("				\
+			"(SELECT $columns FROM $table"		\
+				"WHERE ${where_statement[@]})"	\
+			",'SQL::Select:not found'"		\
+		");" >&3
+	read -u 4 results
+	if ! [[ $results == "SQL::Select:not found" ]]
+	then
+		echo "$results"
+	else
+		return 1
+	fi
+}
+Insert() {
+#Insert table [no_id] <	key value
+#			[key value
+#			[…]]
+	local			\
+		table="$1"	\
+		no_id="${2:-0}"	\
+		insert_keys	\
+		insert_values	\
+		results
+	while read key value
+	do
+		(( ${#insert_keys} )) && insert_keys+=","
+		insert_keys+='`'"$key"'`'
+		(( ${#insert_values} )) && insert_values+=","
+		if [[ $value == NULL ]]
+		then
+			insert_values+="NULL"
+		else
+			insert_values+='"'"${value//\"/\\\"}"'"'
+		fi
+	done
+	echo	"INSERT INTO $table"				\
+				"( $insert_keys )"		\
+			"VALUES"				\
+				"( $insert_values );" >&3
+	(( no_id )) || {
+		echo 'SELECT LAST_INSERT_ID();' >&3
+		read -u 4 results
+		echo "$results"
+	}
+}
+Update(){
+#Update table set_key set_value [set_key set_value […]] <	where_key where_value
+#								[where_key where_value
+#								[…]]
+	local			\
+		table="$1"	\
+		key		\
+		argument	\
+		value		\
+		set_statement	\
+		where_keys	\
+		where_values	\
+		what		\
+		where_statement	\
+		results
+	shift
+	what=key
+	for argument
+	do
+		case $what in
+			key)
+				set_statement="${set_statement:+${set_statement+,}}\`$argument\`"
+				what=value
+			;;
+			value)
+				set_statement="${set_statement}='$argument'"
+				what=key
+			;;
+		esac
+	done
+	while read key value
+	do
+		(( ${#where_statement} )) && where_statement+=( "AND" )
+		if [[ $value == NULL ]]
+		then
+			where_statement+=( "$key is NULL" )
+		else
+			where_statement+=( "$key='$value'" )
+		fi
+	done
+	echo	"UPDATE '$table' SET"		\
+			"$set_statement"	\
+		"WHERE"				\
+			"${where_statement[@]}"	\
+		";" >&3
+}
+InsertOrUpdate() {
+#InsertOrUpdate table set_key set_value [set_key set_value […]] <	where_key where_value
+#									[where_key where_value
+#									[…]]
+	local			\
+		table="$1"	\
+		argument	\
+		key		\
+		keys		\
+		set_keys	\
+		set_values	\
+		value		\
+		values		\
+		what		\
+		results
+	shift
+	what=key
+	for argument
+	do
+		case $what in
+			key)
+				set_keys+=( "$argument" )
+				what=value
+			;;
+			value)
+				set_values+=( "$argument" )
+				what=key
+			;;
+		esac
+	done
+	while read key value
+	do
+		keys+=( "$key" )
+		values+=( "$value" )
+	done
+	if results=$(
+		Select "$table" id < <(
+			for key in ${!keys[@]}
+			do
+				echo "${keys[$key]}" "${values[$key]}"
+			done
+		)
+	)
+	then
+		Update "$table" "$@" < <(
+			for key in ${!keys[@]}
+			do
+				echo "${keys[$key]}" "${values[$key]}"
+			done
+		)
+	else
+		results=$(
+			Insert "$table" < <(
+				for key in ${!set_keys[@]}
+				do
+					echo "${set_keys[$key]}" "${set_values[$key]}"
+				done
+				for key in ${!keys[@]}
+				do
+					echo "${keys[$key]}" "${values[$key]}"
+				done
+			)
+		)
+	fi
+	echo "$results"
+}
+
 getFiles() {
 	:
 }