so kann man alle datenbanken, alle tabellen und dateien nach einer zeichenfolge durchsuchen:

$search = 'gesuchte Zeichenfolge'
$path   = 'D:\'

Get-ChildItem -Path $path -Recurse -File -ErrorAction SilentlyContinue |
Where-Object { $_.Extension -in '.config','.xml','.ini','.json','.txt','.cfg','.conf','.properties','.yaml','.yml','.bat','.cmd','.ps1' } |
Select-String -Pattern $search -SimpleMatch |
Select-Object Path, LineNumber, Line

SET NOCOUNT ON;

DECLARE @Search  NVARCHAR(4000) = N'gesuchte Zeichenfolge';
DECLARE @Pattern NVARCHAR(4000) = N'%' + @Search + N'%';

IF OBJECT_ID('tempdb..#Columns') IS NOT NULL DROP TABLE #Columns;
IF OBJECT_ID('tempdb..#Results') IS NOT NULL DROP TABLE #Results;
IF OBJECT_ID('tempdb..#Errors')  IS NOT NULL DROP TABLE #Errors;

CREATE TABLE #Columns
(
    DatabaseName SYSNAME,
    SchemaName   SYSNAME,
    TableName    SYSNAME,
    ColumnName   SYSNAME,
    DataType     SYSNAME
);

CREATE TABLE #Results
(
    DatabaseName SYSNAME,
    SchemaName   SYSNAME,
    TableName    SYSNAME,
    ColumnName   SYSNAME,
    MatchCount   BIGINT
);

CREATE TABLE #Errors
(
    DatabaseName SYSNAME NULL,
    SchemaName   SYSNAME NULL,
    TableName    SYSNAME NULL,
    ColumnName   SYSNAME NULL,
    ErrorMessage NVARCHAR(4000)
);

DECLARE @Db  SYSNAME;
DECLARE @Sql NVARCHAR(MAX);

--------------------------------------------------------------------------------
-- 1) Alle durchsuchbaren Spalten aus allen User-Datenbanken sammeln
--------------------------------------------------------------------------------
DECLARE db_cursor CURSOR LOCAL FAST_FORWARD FOR
SELECT name
FROM sys.databases
WHERE state_desc = 'ONLINE'
  AND database_id > 4
  AND source_database_id IS NULL;

OPEN db_cursor;
FETCH NEXT FROM db_cursor INTO @Db;

WHILE @@FETCH_STATUS = 0
BEGIN
    SET @Sql = N'
    USE ' + QUOTENAME(@Db) + N';

    INSERT INTO #Columns (DatabaseName, SchemaName, TableName, ColumnName, DataType)
    SELECT
        DB_NAME(),
        s.name,
        t.name,
        c.name,
        ty.name
    FROM sys.tables t
    INNER JOIN sys.schemas s
        ON s.schema_id = t.schema_id
    INNER JOIN sys.columns c
        ON c.object_id = t.object_id
    INNER JOIN sys.types ty
        ON ty.user_type_id = c.user_type_id
    WHERE t.is_ms_shipped = 0
      AND c.is_computed = 0
      AND ty.name IN (N''char'', N''varchar'', N''nchar'', N''nvarchar'', N''text'', N''ntext'', N''xml'');';

    BEGIN TRY
        EXEC (@Sql);
    END TRY
    BEGIN CATCH
        INSERT INTO #Errors (DatabaseName, ErrorMessage)
        VALUES (@Db, ERROR_MESSAGE());
    END CATCH;

    FETCH NEXT FROM db_cursor INTO @Db;
END

CLOSE db_cursor;
DEALLOCATE db_cursor;

--------------------------------------------------------------------------------
-- 2) Jede gefundene Spalte durchsuchen
--------------------------------------------------------------------------------
DECLARE
    @Schema     SYSNAME,
    @Table      SYSNAME,
    @Column     SYSNAME,
    @DataType   SYSNAME,
    @MatchCount BIGINT;

DECLARE col_cursor CURSOR LOCAL FAST_FORWARD FOR
SELECT DatabaseName, SchemaName, TableName, ColumnName, DataType
FROM #Columns
ORDER BY DatabaseName, SchemaName, TableName, ColumnName;

OPEN col_cursor;
FETCH NEXT FROM col_cursor INTO @Db, @Schema, @Table, @Column, @DataType;

WHILE @@FETCH_STATUS = 0
BEGIN
    SET @Sql = N'
    SELECT @MatchCountOUT = COUNT_BIG(*)
    FROM ' + QUOTENAME(@Db) + N'.' + QUOTENAME(@Schema) + N'.' + QUOTENAME(@Table) + N' WITH (NOLOCK)
    WHERE CONVERT(NVARCHAR(4000), ' + QUOTENAME(@Column) + N') LIKE @Pattern;';

    BEGIN TRY
        SET @MatchCount = 0;

        EXEC sp_executesql
            @Sql,
            N'@Pattern NVARCHAR(4000), @MatchCountOUT BIGINT OUTPUT',
            @Pattern = @Pattern,
            @MatchCountOUT = @MatchCount OUTPUT;

        IF @MatchCount > 0
        BEGIN
            INSERT INTO #Results (DatabaseName, SchemaName, TableName, ColumnName, MatchCount)
            VALUES (@Db, @Schema, @Table, @Column, @MatchCount);
        END
    END TRY
    BEGIN CATCH
        INSERT INTO #Errors (DatabaseName, SchemaName, TableName, ColumnName, ErrorMessage)
        VALUES (@Db, @Schema, @Table, @Column, ERROR_MESSAGE());
    END CATCH;

    FETCH NEXT FROM col_cursor INTO @Db, @Schema, @Table, @Column, @DataType;
END

CLOSE col_cursor;
DEALLOCATE col_cursor;

--------------------------------------------------------------------------------
-- 3) Treffer
--------------------------------------------------------------------------------
SELECT
    DatabaseName,
    SchemaName,
    TableName,
    ColumnName,
    MatchCount
FROM #Results
ORDER BY MatchCount DESC, DatabaseName, SchemaName, TableName, ColumnName;

--------------------------------------------------------------------------------
-- 4) Fehler
--------------------------------------------------------------------------------
SELECT *
FROM #Errors
ORDER BY DatabaseName, SchemaName, TableName, ColumnName;

(hier muss evtl. eine fehlerhafte spalte aus dem script entfernt werden)