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cond.go
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cond.go
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// Copyright 2018 Huan Du. All rights reserved.
// Licensed under the MIT license that can be found in the LICENSE file.
package sqlbuilder
const (
lparen = "("
rparen = ")"
opOR = " OR "
opAND = " AND "
opNOT = "NOT "
)
const minIndexBase = 256
// Cond provides several helper methods to build conditions.
type Cond struct {
Args *Args
}
// NewCond returns a new Cond.
func NewCond() *Cond {
return &Cond{
Args: &Args{
// Based on the discussion in #174, users may call this method to create
// `Cond` for building various conditions, which is a misuse, but we
// cannot completely prevent this error. To facilitate users in
// identifying the issue when they make mistakes and to avoid
// unexpected stackoverflows, the base index for `Args` is
// deliberately set to a larger non-zero value here. This can
// significantly reduce the likelihood of issues and allows for
// timely error notification to users.
indexBase: minIndexBase,
},
}
}
// Equal is used to construct the expression "field = value".
func (c *Cond) Equal(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" = ")
ctx.WriteValue(value)
},
})
}
// E is an alias of Equal.
func (c *Cond) E(field string, value interface{}) string {
return c.Equal(field, value)
}
// EQ is an alias of Equal.
func (c *Cond) EQ(field string, value interface{}) string {
return c.Equal(field, value)
}
// NotEqual is used to construct the expression "field <> value".
func (c *Cond) NotEqual(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" <> ")
ctx.WriteValue(value)
},
})
}
// NE is an alias of NotEqual.
func (c *Cond) NE(field string, value interface{}) string {
return c.NotEqual(field, value)
}
// NEQ is an alias of NotEqual.
func (c *Cond) NEQ(field string, value interface{}) string {
return c.NotEqual(field, value)
}
// GreaterThan is used to construct the expression "field > value".
func (c *Cond) GreaterThan(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" > ")
ctx.WriteValue(value)
},
})
}
// G is an alias of GreaterThan.
func (c *Cond) G(field string, value interface{}) string {
return c.GreaterThan(field, value)
}
// GT is an alias of GreaterThan.
func (c *Cond) GT(field string, value interface{}) string {
return c.GreaterThan(field, value)
}
// GreaterEqualThan is used to construct the expression "field >= value".
func (c *Cond) GreaterEqualThan(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" >= ")
ctx.WriteValue(value)
},
})
}
// GE is an alias of GreaterEqualThan.
func (c *Cond) GE(field string, value interface{}) string {
return c.GreaterEqualThan(field, value)
}
// GTE is an alias of GreaterEqualThan.
func (c *Cond) GTE(field string, value interface{}) string {
return c.GreaterEqualThan(field, value)
}
// LessThan is used to construct the expression "field < value".
func (c *Cond) LessThan(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" < ")
ctx.WriteValue(value)
},
})
}
// L is an alias of LessThan.
func (c *Cond) L(field string, value interface{}) string {
return c.LessThan(field, value)
}
// LT is an alias of LessThan.
func (c *Cond) LT(field string, value interface{}) string {
return c.LessThan(field, value)
}
// LessEqualThan is used to construct the expression "field <= value".
func (c *Cond) LessEqualThan(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" <= ")
ctx.WriteValue(value)
},
})
}
// LE is an alias of LessEqualThan.
func (c *Cond) LE(field string, value interface{}) string {
return c.LessEqualThan(field, value)
}
// LTE is an alias of LessEqualThan.
func (c *Cond) LTE(field string, value interface{}) string {
return c.LessEqualThan(field, value)
}
// In is used to construct the expression "field IN (value...)".
func (c *Cond) In(field string, values ...interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" IN (")
ctx.WriteValues(values, ", ")
ctx.WriteString(")")
},
})
}
// NotIn is used to construct the expression "field NOT IN (value...)".
func (c *Cond) NotIn(field string, values ...interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" NOT IN (")
ctx.WriteValues(values, ", ")
ctx.WriteString(")")
},
})
}
// Like is used to construct the expression "field LIKE value".
func (c *Cond) Like(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" LIKE ")
ctx.WriteValue(value)
},
})
}
// ILike is used to construct the expression "field ILIKE value".
//
// When the database system does not support the ILIKE operator,
// the ILike method will return "LOWER(field) LIKE LOWER(value)"
// to simulate the behavior of the ILIKE operator.
func (c *Cond) ILike(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
switch ctx.Flavor {
case PostgreSQL, SQLite:
ctx.WriteString(field)
ctx.WriteString(" ILIKE ")
ctx.WriteValue(value)
default:
// Use LOWER to simulate ILIKE.
ctx.WriteString("LOWER(")
ctx.WriteString(field)
ctx.WriteString(") LIKE LOWER(")
ctx.WriteValue(value)
ctx.WriteString(")")
}
},
})
}
// NotLike is used to construct the expression "field NOT LIKE value".
func (c *Cond) NotLike(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" NOT LIKE ")
ctx.WriteValue(value)
},
})
}
// NotILike is used to construct the expression "field NOT ILIKE value".
//
// When the database system does not support the ILIKE operator,
// the NotILike method will return "LOWER(field) NOT LIKE LOWER(value)"
// to simulate the behavior of the ILIKE operator.
func (c *Cond) NotILike(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
switch ctx.Flavor {
case PostgreSQL, SQLite:
ctx.WriteString(field)
ctx.WriteString(" NOT ILIKE ")
ctx.WriteValue(value)
default:
// Use LOWER to simulate ILIKE.
ctx.WriteString("LOWER(")
ctx.WriteString(field)
ctx.WriteString(") NOT LIKE LOWER(")
ctx.WriteValue(value)
ctx.WriteString(")")
}
},
})
}
// IsNull is used to construct the expression "field IS NULL".
func (c *Cond) IsNull(field string) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" IS NULL")
},
})
}
// IsNotNull is used to construct the expression "field IS NOT NULL".
func (c *Cond) IsNotNull(field string) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" IS NOT NULL")
},
})
}
// Between is used to construct the expression "field BETWEEN lower AND upper".
func (c *Cond) Between(field string, lower, upper interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" BETWEEN ")
ctx.WriteValue(lower)
ctx.WriteString(" AND ")
ctx.WriteValue(upper)
},
})
}
// NotBetween is used to construct the expression "field NOT BETWEEN lower AND upper".
func (c *Cond) NotBetween(field string, lower, upper interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" NOT BETWEEN ")
ctx.WriteValue(lower)
ctx.WriteString(" AND ")
ctx.WriteValue(upper)
},
})
}
// Or is used to construct the expression OR logic like "expr1 OR expr2 OR expr3".
func (c *Cond) Or(orExpr ...string) string {
if len(orExpr) == 0 {
return ""
}
exprByteLen := estimateStringsBytes(orExpr)
if exprByteLen == 0 {
return ""
}
buf := newStringBuilder()
// Ensure that there is only 1 memory allocation.
size := len(lparen) + len(rparen) + (len(orExpr)-1)*len(opOR) + exprByteLen
buf.Grow(size)
buf.WriteString(lparen)
buf.WriteStrings(orExpr, opOR)
buf.WriteString(rparen)
return buf.String()
}
// And is used to construct the expression AND logic like "expr1 AND expr2 AND expr3".
func (c *Cond) And(andExpr ...string) string {
if len(andExpr) == 0 {
return ""
}
exprByteLen := estimateStringsBytes(andExpr)
if exprByteLen == 0 {
return ""
}
buf := newStringBuilder()
// Ensure that there is only 1 memory allocation.
size := len(lparen) + len(rparen) + (len(andExpr)-1)*len(opAND) + exprByteLen
buf.Grow(size)
buf.WriteString(lparen)
buf.WriteStrings(andExpr, opAND)
buf.WriteString(rparen)
return buf.String()
}
// Not is used to construct the expression "NOT expr".
func (c *Cond) Not(notExpr string) string {
if len(notExpr) == 0 {
return ""
}
buf := newStringBuilder()
// Ensure that there is only 1 memory allocation.
size := len(opNOT) + len(notExpr)
buf.Grow(size)
buf.WriteString(opNOT)
buf.WriteString(notExpr)
return buf.String()
}
// Exists is used to construct the expression "EXISTS (subquery)".
func (c *Cond) Exists(subquery interface{}) string {
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString("EXISTS (")
ctx.WriteValue(subquery)
ctx.WriteString(")")
},
})
}
// NotExists is used to construct the expression "NOT EXISTS (subquery)".
func (c *Cond) NotExists(subquery interface{}) string {
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString("NOT EXISTS (")
ctx.WriteValue(subquery)
ctx.WriteString(")")
},
})
}
// Any is used to construct the expression "field op ANY (value...)".
func (c *Cond) Any(field, op string, values ...interface{}) string {
if len(field) == 0 || len(op) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" ")
ctx.WriteString(op)
ctx.WriteString(" ANY (")
ctx.WriteValues(values, ", ")
ctx.WriteString(")")
},
})
}
// All is used to construct the expression "field op ALL (value...)".
func (c *Cond) All(field, op string, values ...interface{}) string {
if len(field) == 0 || len(op) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" ")
ctx.WriteString(op)
ctx.WriteString(" ALL (")
ctx.WriteValues(values, ", ")
ctx.WriteString(")")
},
})
}
// Some is used to construct the expression "field op SOME (value...)".
func (c *Cond) Some(field, op string, values ...interface{}) string {
if len(field) == 0 || len(op) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
ctx.WriteString(field)
ctx.WriteString(" ")
ctx.WriteString(op)
ctx.WriteString(" SOME (")
ctx.WriteValues(values, ", ")
ctx.WriteString(")")
},
})
}
// IsDistinctFrom is used to construct the expression "field IS DISTINCT FROM value".
//
// When the database system does not support the IS DISTINCT FROM operator,
// the NotILike method will return "NOT field <=> value" for MySQL or a
// "CASE ... WHEN ... ELSE ... END" expression to simulate the behavior of
// the IS DISTINCT FROM operator.
func (c *Cond) IsDistinctFrom(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
switch ctx.Flavor {
case PostgreSQL, SQLite, SQLServer:
ctx.WriteString(field)
ctx.WriteString(" IS DISTINCT FROM ")
ctx.WriteValue(value)
case MySQL:
ctx.WriteString("NOT ")
ctx.WriteString(field)
ctx.WriteString(" <=> ")
ctx.WriteValue(value)
default:
// CASE
// WHEN field IS NULL AND value IS NULL THEN 0
// WHEN field IS NOT NULL AND value IS NOT NULL AND field = value THEN 0
// ELSE 1
// END = 1
ctx.WriteString("CASE WHEN ")
ctx.WriteString(field)
ctx.WriteString(" IS NULL AND ")
ctx.WriteValue(value)
ctx.WriteString(" IS NULL THEN 0 WHEN ")
ctx.WriteString(field)
ctx.WriteString(" IS NOT NULL AND ")
ctx.WriteValue(value)
ctx.WriteString(" IS NOT NULL AND ")
ctx.WriteString(field)
ctx.WriteString(" = ")
ctx.WriteValue(value)
ctx.WriteString(" THEN 0 ELSE 1 END = 1")
}
},
})
}
// IsNotDistinctFrom is used to construct the expression "field IS NOT DISTINCT FROM value".
//
// When the database system does not support the IS NOT DISTINCT FROM operator,
// the NotILike method will return "field <=> value" for MySQL or a
// "CASE ... WHEN ... ELSE ... END" expression to simulate the behavior of
// the IS NOT DISTINCT FROM operator.
func (c *Cond) IsNotDistinctFrom(field string, value interface{}) string {
if len(field) == 0 {
return ""
}
return c.Var(condBuilder{
Builder: func(ctx *argsCompileContext) {
switch ctx.Flavor {
case PostgreSQL, SQLite, SQLServer:
ctx.WriteString(field)
ctx.WriteString(" IS NOT DISTINCT FROM ")
ctx.WriteValue(value)
case MySQL:
ctx.WriteString(field)
ctx.WriteString(" <=> ")
ctx.WriteValue(value)
default:
// CASE
// WHEN field IS NULL AND value IS NULL THEN 1
// WHEN field IS NOT NULL AND value IS NOT NULL AND field = value THEN 1
// ELSE 0
// END = 1
ctx.WriteString("CASE WHEN ")
ctx.WriteString(field)
ctx.WriteString(" IS NULL AND ")
ctx.WriteValue(value)
ctx.WriteString(" IS NULL THEN 1 WHEN ")
ctx.WriteString(field)
ctx.WriteString(" IS NOT NULL AND ")
ctx.WriteValue(value)
ctx.WriteString(" IS NOT NULL AND ")
ctx.WriteString(field)
ctx.WriteString(" = ")
ctx.WriteValue(value)
ctx.WriteString(" THEN 1 ELSE 0 END = 1")
}
},
})
}
// Var returns a placeholder for value.
func (c *Cond) Var(value interface{}) string {
return c.Args.Add(value)
}
type condBuilder struct {
Builder func(ctx *argsCompileContext)
}
func estimateStringsBytes(strs []string) (n int) {
for _, s := range strs {
n += len(s)
}
return
}