feat(sql): ISqlDialect + SqlServerDialect with golden catalog SQL
The dialect owns the two things ADO.NET's System.Data.Common base types cannot abstract: identifier quoting and the metadata-catalog SQL. It is the driver's SQL-injection boundary — values always bind as DbParameters, identifiers cannot, so the few that reach a command text are catalog- sourced and pass through QuoteIdentifier. QuoteIdentifier brackets one identifier part and doubles embedded ] (the only metacharacter that can terminate a bracketed identifier early); rejects null/empty/whitespace, >128 chars (T-SQL sysname ceiling), and any control character (incl. NUL) as ArgumentException, without echoing the untrusted value into the message. MapColumnType folds the design §3.7 families case-insensitively and never throws — an unrecognised family falls back to String so a browse over an exotic column still renders; timestamp/rowversion and time are deliberately NOT mapped to DateTime. Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
This commit is contained in:
Joseph Doherty
@@ -0,0 +1,127 @@
|
||||
using System.Data.Common;
|
||||
using Microsoft.Data.SqlClient;
|
||||
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
|
||||
using ZB.MOM.WW.OtOpcUa.Driver.Sql.Contracts;
|
||||
|
||||
namespace ZB.MOM.WW.OtOpcUa.Driver.Sql;
|
||||
|
||||
/// <summary>
|
||||
/// Microsoft SQL Server dialect (design §2.2) — the only provider v1 constructs. Bracket quoting,
|
||||
/// <c>INFORMATION_SCHEMA</c> catalog SQL, and the design §3.7 type-family map.
|
||||
/// <para>Stateless and immutable, so a single instance is safely shared by the driver's poll reader and
|
||||
/// the AdminUI browse session.</para>
|
||||
/// </summary>
|
||||
public sealed class SqlServerDialect : ISqlDialect
|
||||
{
|
||||
/// <summary>
|
||||
/// T-SQL's regular-identifier ceiling (<c>sysname</c> = <c>nvarchar(128)</c>). Enforced because a
|
||||
/// longer string cannot name a real catalog object — it is either a config mistake or padding, and
|
||||
/// rejecting it keeps the quoted output bounded.
|
||||
/// </summary>
|
||||
internal const int MaxIdentifierLength = 128;
|
||||
|
||||
/// <inheritdoc/>
|
||||
public SqlProvider Provider => SqlProvider.SqlServer;
|
||||
|
||||
/// <inheritdoc/>
|
||||
public DbProviderFactory Factory => SqlClientFactory.Instance;
|
||||
|
||||
/// <inheritdoc/>
|
||||
public string LivenessSql => "SELECT 1";
|
||||
|
||||
/// <inheritdoc/>
|
||||
public string ListSchemasSql =>
|
||||
"SELECT DISTINCT TABLE_SCHEMA FROM INFORMATION_SCHEMA.TABLES ORDER BY TABLE_SCHEMA";
|
||||
|
||||
/// <inheritdoc/>
|
||||
public string ListTablesSql =>
|
||||
"SELECT TABLE_NAME, TABLE_TYPE FROM INFORMATION_SCHEMA.TABLES " +
|
||||
"WHERE TABLE_SCHEMA = @schema ORDER BY TABLE_NAME";
|
||||
|
||||
/// <inheritdoc/>
|
||||
public string ListColumnsSql =>
|
||||
"SELECT COLUMN_NAME, DATA_TYPE, IS_NULLABLE FROM INFORMATION_SCHEMA.COLUMNS " +
|
||||
"WHERE TABLE_SCHEMA = @schema AND TABLE_NAME = @table ORDER BY ORDINAL_POSITION";
|
||||
|
||||
/// <summary>
|
||||
/// Brackets one identifier part, doubling any embedded <c>]</c> — the T-SQL escape rule, and the only
|
||||
/// metacharacter that could terminate a bracketed identifier early. <c>[</c>, quotes, semicolons and
|
||||
/// comment markers are inert inside brackets and are therefore passed through unchanged.
|
||||
/// </summary>
|
||||
/// <remarks>
|
||||
/// <para><b>Rejects</b> (all as <see cref="ArgumentException"/>): null / empty / all-whitespace; longer
|
||||
/// than <see cref="MaxIdentifierLength"/>; any control character (which covers embedded NUL, and the
|
||||
/// C0/C1 ranges that can truncate or corrupt a logged/audited statement).</para>
|
||||
/// <para>The rejection messages deliberately do <b>not</b> echo the offending value — it is untrusted
|
||||
/// input and this exception's text reaches the driver log.</para>
|
||||
/// <para>Rejection is a backstop, not the primary defence: an identifier only reaches here after being
|
||||
/// validated against the live catalog (design §8.1).</para>
|
||||
/// </remarks>
|
||||
/// <param name="ident">The bare, unquoted identifier part.</param>
|
||||
/// <returns>The bracket-quoted identifier.</returns>
|
||||
/// <exception cref="ArgumentException">The value cannot be a valid SQL Server identifier.</exception>
|
||||
public string QuoteIdentifier(string ident)
|
||||
{
|
||||
if (string.IsNullOrWhiteSpace(ident))
|
||||
throw new ArgumentException(
|
||||
"A SQL identifier must be a non-empty, non-whitespace name.", nameof(ident));
|
||||
|
||||
if (ident.Length > MaxIdentifierLength)
|
||||
throw new ArgumentException(
|
||||
$"A SQL Server identifier may not exceed {MaxIdentifierLength} characters (got {ident.Length}).",
|
||||
nameof(ident));
|
||||
|
||||
foreach (var ch in ident)
|
||||
{
|
||||
if (char.IsControl(ch))
|
||||
throw new ArgumentException(
|
||||
"A SQL identifier may not contain control characters (including NUL).", nameof(ident));
|
||||
}
|
||||
|
||||
return string.Concat("[", ident.Replace("]", "]]", StringComparison.Ordinal), "]");
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Folds an <c>INFORMATION_SCHEMA.COLUMNS.DATA_TYPE</c> family name onto a
|
||||
/// <see cref="DriverDataType"/> per design §3.7.
|
||||
/// </summary>
|
||||
/// <remarks>
|
||||
/// <para><b>Precision caveat:</b> <c>decimal</c> / <c>numeric</c> / <c>money</c> / <c>smallmoney</c>
|
||||
/// collapse to <see cref="DriverDataType.Float64"/> in v1. A .NET <c>decimal</c> carries more
|
||||
/// significant digits than a <c>double</c>, so a high-precision column (e.g. <c>decimal(38,10)</c>)
|
||||
/// loses low-order digits. Authoring an explicit <c>"type": "String"</c> on the tag preserves the exact
|
||||
/// textual value when that matters.</para>
|
||||
/// <para><b>Fallback:</b> an unrecognised family maps to <see cref="DriverDataType.String"/> and never
|
||||
/// throws — a schema browse must render a table containing an exotic column (<c>xml</c>,
|
||||
/// <c>geography</c>, <c>hierarchyid</c>, <c>sql_variant</c>, a CLR UDT, <c>varbinary</c>) rather than
|
||||
/// crash on it. Null/blank input takes the same fallback.</para>
|
||||
/// <para><b>Deliberate non-mappings:</b> SQL Server's <c>timestamp</c>/<c>rowversion</c> is an opaque
|
||||
/// 8-byte row version, <em>not</em> a date — it falls back to <see cref="DriverDataType.String"/>
|
||||
/// rather than being mistaken for a <see cref="DriverDataType.DateTime"/>. <c>time</c> is a
|
||||
/// time-of-day span, likewise not a point in time, and takes the same fallback.</para>
|
||||
/// <para><c>tinyint</c> widens to <see cref="DriverDataType.Int16"/> (it is unsigned 0–255 in T-SQL, so
|
||||
/// a signed 8-bit type would not hold it, and the driver type set has no <c>Byte</c>).</para>
|
||||
/// </remarks>
|
||||
/// <param name="sqlDataType">The bare SQL type family name; matched case-insensitively.</param>
|
||||
/// <returns>The mapped driver data type, or <see cref="DriverDataType.String"/> when unrecognised.</returns>
|
||||
public DriverDataType MapColumnType(string sqlDataType)
|
||||
{
|
||||
if (string.IsNullOrWhiteSpace(sqlDataType)) return DriverDataType.String;
|
||||
|
||||
return sqlDataType.Trim().ToLowerInvariant() switch
|
||||
{
|
||||
"bit" or "boolean" => DriverDataType.Boolean,
|
||||
"tinyint" or "smallint" => DriverDataType.Int16,
|
||||
"int" or "integer" => DriverDataType.Int32,
|
||||
"bigint" => DriverDataType.Int64,
|
||||
"real" => DriverDataType.Float32,
|
||||
"float" or "double" or "double precision"
|
||||
or "decimal" or "numeric" or "money" or "smallmoney" => DriverDataType.Float64,
|
||||
"char" or "nchar" or "varchar" or "nvarchar" or "text" or "ntext"
|
||||
or "uniqueidentifier" => DriverDataType.String,
|
||||
"date" or "datetime" or "datetime2" or "smalldatetime"
|
||||
or "datetimeoffset" => DriverDataType.DateTime,
|
||||
_ => DriverDataType.String,
|
||||
};
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user