chore: initial git load of code space

src/Strata.SqlTools.PostgreSql/Visitors/CommandVisitor.cs

@@ -0,0 +1,62 @@
+using Strata.SqlTools.SqlBreakdown.Expressions.Conditional;
+using SqlServerCommandVisitor = Strata.SqlTools.Visitors.SqlServer.CommandVisitor;
+
+namespace Strata.SqlTools.Visitors.PostgreSql;
+
+/// <summary>
+/// Implements the visitor pattern to convert SQL expression objects into PostgreSQL-compatible SQL command strings.
+/// Inherits from SqlServer.CommandVisitor and overrides only the dialect-specific formatting methods.
+/// </summary>
+public class CommandVisitor : SqlServerCommandVisitor
+{
+    private static int _parameterIndex = 1;
+
+    /// <summary>
+    /// Formats an identifier for PostgreSQL using double-quote quoting.
+    /// </summary>
+    /// <param name="identifier">The identifier to format.</param>
+    /// <returns>The quoted identifier.</returns>
+    protected override string FormatIdentifier(string identifier) => $"\"{identifier}\"";
+
+    /// <summary>
+    /// Formats a parameter name for PostgreSQL using positional parameter syntax.
+    /// Parameters in PostgreSQL are referenced as $1, $2, $3, etc.
+    /// </summary>
+    /// <param name="parameterName">The parameter name to format.</param>
+    /// <returns>A SQL string in the format "$position" where position is a number.</returns>
+    protected override string FormatParameterName(string parameterName)
+    {
+        // PostgreSQL uses positional parameters: $1, $2, $3, etc.
+        return $"${_parameterIndex++}";
+    }
+
+    /// <summary>
+    /// Formats a boolean literal for PostgreSQL using TRUE/FALSE keywords.
+    /// </summary>
+    /// <param name="value">The boolean value to format.</param>
+    /// <returns>The string "true" or "false" in lowercase.</returns>
+    protected override string FormatBooleanLiteral(bool value) => value ? "true" : "false";
+
+    /// <summary>
+    /// Formats a string literal for PostgreSQL with proper escaping of single quotes.
+    /// </summary>
+    /// <param name="value">The string value to format.</param>
+    /// <returns>A SQL string literal enclosed in single quotes with escaped quotes.</returns>
+    protected override string FormatStringLiteral(string value)
+    {
+        // PostgreSQL: escape single quotes by doubling them
+        var escaped = value.Replace("'", "''");
+        return $"'{escaped}'";
+    }
+
+    /// <summary>
+    /// Formats a case-insensitive LIKE expression for PostgreSQL using ILIKE keyword.
+    /// </summary>
+    /// <param name="likeExpression">The LIKE expression to format.</param>
+    /// <returns>A SQL string in the format "expression ILIKE pattern".</returns>
+    protected override string FormatCaseInsensitiveLike(LikeExpression likeExpression)
+    {
+        return $"{likeExpression.Subject.Accept(this)} ILIKE {likeExpression.Pattern.Accept(this)}";
+    }
+}
+