first commit

qry.go

@@ -0,0 +1,240 @@
+// Patial Tech.
+// Author, Ankit Patial
+
+package pgm
+
+import (
+	"context"
+	"strconv"
+	"strings"
+
+	"github.com/jackc/pgx/v5"
+)
+
+type (
+	Clause interface {
+		Select(fields ...Field) SelectClause
+		// Insert() InsertSet
+		// Update() UpdateSet
+		// Delete() WhereOrExec
+	}
+
+	SelectClause interface {
+		// Join and Inner Join are same
+		Join(m Table, t1Field, t2Field Field) SelectClause
+		LeftJoin(m Table, t1Field, t2Field Field) SelectClause
+		RightJoin(m Table, t1Field, t2Field Field) SelectClause
+		FullJoin(m Table, t1Field, t2Field Field) SelectClause
+		CrossJoin(m Table) SelectClause
+		WhereClause
+		OrderByClause
+		GroupByClause
+		LimitClause
+		OffsetClause
+		Query
+		raw(prefixArgs []any) (string, []any)
+	}
+
+	WhereClause interface {
+		Where(cond ...Conditioner) AfterWhere
+	}
+
+	AfterWhere interface {
+		WhereClause
+		GroupByClause
+		OrderByClause
+		LimitClause
+		OffsetClause
+		Query
+	}
+
+	GroupByClause interface {
+		GroupBy(fields ...Field) AfterGroupBy
+	}
+
+	AfterGroupBy interface {
+		HavinClause
+		OrderByClause
+		LimitClause
+		OffsetClause
+		Query
+	}
+
+	HavinClause interface {
+		Having(cond ...Conditioner) AfterHaving
+	}
+
+	AfterHaving interface {
+		OrderByClause
+		LimitClause
+		OffsetClause
+		Query
+	}
+
+	OrderByClause interface {
+		OrderBy(fields ...Field) AfterOrderBy
+	}
+
+	AfterOrderBy interface {
+		LimitClause
+		OffsetClause
+		Query
+	}
+
+	LimitClause interface {
+		Limit(v int) AfterLimit
+	}
+
+	AfterLimit interface {
+		OffsetClause
+		Query
+	}
+
+	OffsetClause interface {
+		Offset(v int) AfterOffset
+	}
+
+	AfterOffset interface {
+		LimitClause
+		Query
+	}
+
+	Conditioner interface {
+		Condition(args *[]any, idx int) string
+	}
+
+	Insert interface {
+		Set(field Field, val any) InsertClause
+		SetMap(fields map[Field]any) InsertClause
+	}
+
+	InsertClause interface {
+		Insert
+		Returning(field Field) First
+		OnConflict(fields ...Field) Do
+		Execute
+		Stringer
+	}
+
+	Do interface {
+		DoNothing() Execute
+		DoUpdate(fields ...Field) Execute
+	}
+
+	Update interface {
+		Set(field Field, val any) UpdateClause
+		SetMap(fields map[Field]any) UpdateClause
+	}
+
+	UpdateClause interface {
+		Update
+		Where(cond ...Conditioner) WhereOrExec
+	}
+
+	WhereOrExec interface {
+		Where(cond ...Conditioner) WhereOrExec
+		Execute
+	}
+
+	Query interface {
+		First
+		All
+		Stringer
+	}
+
+	First interface {
+		First(ctx context.Context, dest ...any) error
+		FirstTx(ctx context.Context, tx pgx.Tx, dest ...any) error
+		Stringer
+	}
+
+	All interface {
+		// Query rows
+		//
+		// don't forget to close() rows
+		All(ctx context.Context, rows RowsCb) error
+		// Query rows
+		//
+		// don't forget to close() rows
+		AllTx(ctx context.Context, tx pgx.Tx, rows RowsCb) error
+	}
+
+	Execute interface {
+		Exec(ctx context.Context) error
+		ExecTx(ctx context.Context, tx pgx.Tx) error
+		Stringer
+	}
+
+	Stringer interface {
+		String() string
+	}
+
+	RowScanner interface {
+		Scan(dest ...any) error
+	}
+
+	RowsCb func(row RowScanner) error
+)
+
+func joinFileds(fields []Field) string {
+	sb := getSB()
+	defer putSB(sb)
+	for i, f := range fields {
+		if i == 0 {
+			sb.WriteString(f.String())
+		} else {
+			sb.WriteString(", ")
+			sb.WriteString(f.String())
+		}
+	}
+
+	return sb.String()
+}
+
+func And(cond ...Conditioner) Conditioner {
+	return &CondGroup{op: " AND ", cond: cond}
+}
+
+func Or(cond ...Conditioner) Conditioner {
+	return &CondGroup{op: " OR ", cond: cond}
+}
+
+func (cv *Cond) Condition(args *[]any, argIdx int) string {
+	// 1. condition with subquery
+	if cv.action == CondActionSubQuery {
+		qStr, newArgs := cv.Val.(SelectClause).raw(*args)
+		*args = newArgs
+		return cv.Field + strings.Replace(cv.op, "$", qStr, 1)
+	}
+
+	// 2. normal condition
+	*args = append(*args, cv.Val)
+	var op string
+	if strings.HasSuffix(cv.op, "$") {
+		op = cv.op + strconv.Itoa(argIdx+1)
+	} else {
+		op = strings.Replace(cv.op, "$", "$"+strconv.Itoa(argIdx+1), 1)
+	}
+
+	if cv.action == CondActionNeedToClose {
+		return cv.Field + op + ")"
+	}
+	return cv.Field + op
+}
+
+func (c *CondGroup) Condition(args *[]any, argIdx int) string {
+	sb := getSB()
+	defer putSB(sb)
+
+	sb.WriteString("(")
+	for i, cond := range c.cond {
+		if i == 0 {
+			sb.WriteString(cond.Condition(args, argIdx+i))
+		} else {
+			sb.WriteString(c.op)
+			sb.WriteString(cond.Condition(args, argIdx+i))
+		}
+	}
+	sb.WriteString(")")
+	return sb.String()
+}