github.com/cockroachdb/cockroachdb-parser@v0.23.3-0.20240213214944-911057d40c9a/pkg/sql/sem/tree/comment_on_column.go (about)

     1  // Copyright 2018 The Cockroach Authors.
     2  //
     3  // Use of this software is governed by the Business Source License
     4  // included in the file licenses/BSL.txt.
     5  //
     6  // As of the Change Date specified in that file, in accordance with
     7  // the Business Source License, use of this software will be governed
     8  // by the Apache License, Version 2.0, included in the file
     9  // licenses/APL.txt.
    10  
    11  package tree
    12  
    13  import "github.com/cockroachdb/cockroachdb-parser/pkg/sql/lexbase"
    14  
    15  // CommentOnColumn represents an COMMENT ON COLUMN statement.
    16  type CommentOnColumn struct {
    17  	*ColumnItem
    18  	Comment *string
    19  }
    20  
    21  // Format implements the NodeFormatter interface.
    22  func (n *CommentOnColumn) Format(ctx *FmtCtx) {
    23  	ctx.WriteString("COMMENT ON COLUMN ")
    24  	ctx.FormatNode(n.ColumnItem)
    25  	ctx.WriteString(" IS ")
    26  	if n.Comment != nil {
    27  		// TODO(knz): Replace all this with ctx.FormatNode
    28  		// when COMMENT supports expressions.
    29  		if ctx.flags.HasFlags(FmtHideConstants) {
    30  			ctx.WriteString("'_'")
    31  		} else {
    32  			lexbase.EncodeSQLStringWithFlags(&ctx.Buffer, *n.Comment, ctx.flags.EncodeFlags())
    33  		}
    34  	} else {
    35  		ctx.WriteString("NULL")
    36  	}
    37  }